Add curator Movement links config with proof URLs and admin-gated delete votes.

Persist lineage in PostgreSQL, seed documented edges, and keep timeline/tree consumers API-backed with a static fallback.

Co-authored-by: Cursor <cursoragent@cursor.com>

Documentation/API.md

@@ -125,11 +125,14 @@ Each list entry includes `created_at`, `username`, `user_role`, `action`, `resou
 | `POST /api/artists/:id/upload-portrait` | `images` | `artist.upload_portrait` |
 | `/api/translations/*` | `translations` | `translation.*` |
 | `/api/influences/*` | `influences` | `influence.*` |
+| `POST` `/api/movement-links` | `influences` | `movement_link.create` |
+| `POST`/`DELETE` `/api/movement-links` votes | `influences` | `movement_link.delete_vote*` |
+| `DELETE` `/api/movement-links/:id` | admin role | `movement_link.delete` |
 | Tour admin (`/api/tours/admin`, POST/PATCH/DELETE, stops) | `tours` | `tour.*` |
 | `/api/users/*` | `users` | `user.*` |
 | `/api/audit/*` | admin role | — (read) |
 
-**Public** (no login): all catalog `GET` routes, `POST /api/artists/:id/preload-images`, `POST /api/movements/:id/preload-images` (local file linking for 3D halls), `/images`, SPA static.
+**Public** (no login): all catalog `GET` routes, `GET /api/movement-links`, `POST /api/artists/:id/preload-images`, `POST /api/movements/:id/preload-images` (local file linking for 3D halls), `/images`, SPA static.
 
 Staff mutations are recorded in `curator_audit_log` with `user_id` (see [DB_structure.md](DB_structure.md)). Browse via admin **Activity** UI or `/api/audit`.
 
@@ -261,6 +264,23 @@ Public painting detail still exposes read-only `influencedBy` / `influenced` (un
 
 ---
 
+## Movement lineage links
+
+Timeline / Tree of Art predecessor→successor edges. Base path: `/api/movement-links`. See [data-and-images.md](data-and-images.md#movement-lineage-timeline--tree-of-art).
+
+| Method | Path | Auth | Purpose |
+|--------|------|------|---------|
+| `GET` | `/api/movement-links` | public | List links (`q`, pagination); seeds defaults when empty; includes `delete_vote_count` |
+| `POST` | `/api/movement-links` | curator (`influences`) | Create `{ sourceMovementId, targetMovementId, proofUrl, proofLabel?, linkYearApprox?, notes? }` — **proofUrl required** |
+| `GET` | `/api/movement-links/:id/delete-votes` | curator (`influences`) | List delete votes (username + reason) |
+| `POST` | `/api/movement-links/:id/delete-votes` | curator (`influences`) | Vote to delete `{ reason }` (min 10 characters) |
+| `DELETE` | `/api/movement-links/:id/delete-votes/me` | curator (`influences`) | Withdraw own delete vote |
+| `DELETE` | `/api/movement-links/:id` | **admin** | Hard delete (curators vote instead) |
+
+Audit: `movement_link.create` / `movement_link.delete_vote` / `movement_link.delete_vote_withdraw` / `movement_link.delete`.
+
+---
+
 ## Tours
 
 Base path: `/api/tours`. Full guide: [tours.md](tours.md).

Documentation/DB_structure.md

@@ -33,6 +33,8 @@ erDiagram
   paintings ||--o{ painting_influence_sources : influenced_by
   artists ||--o{ painting_influence_sources : artist_source
   art_movements ||--o{ painting_influence_sources : movement_source
+  art_movements ||--o{ movement_lineage_links : source
+  art_movements ||--o{ movement_lineage_links : target
 ```
 
 ## Tables
@@ -213,6 +215,36 @@ Unique index on `(painting_id, source_type, source_painting_id, source_artist_id
 
 **Canonical influence store.** Used by all API influence queries: painting detail (`influencedBy`, `influenced`), `has_influence_links`, and artist hall navigation (predecessors / successors). Legacy `painting_influences` rows are backfilled here on migration; new curated painting edges are written to both tables by `update-influences`.
 
+### `movement_lineage_links`
+
+Art-movement predecessor → successor edges for the timeline flow and Tree of Art. Migration: `db/migrate-movement-links.sql`.
+
+| Column | Type | Notes |
+|--------|------|-------|
+| `id` | SERIAL PK | |
+| `source_movement_id` | FK → `art_movements` | Predecessor |
+| `target_movement_id` | FK → `art_movements` | Successor (must differ from source) |
+| `link_year_approx` | INTEGER | Approximate transition year |
+| `proof_url` | TEXT NOT NULL | Required literature / museum / web citation URL |
+| `proof_label` | TEXT | Short display label for the proof |
+| `notes` | TEXT | Optional curator note |
+| `created_by` | FK → `users` | Curator who added the row |
+| `created_at` / `updated_at` | TIMESTAMPTZ | |
+
+Unique on `(source_movement_id, target_movement_id)`.
+
+### `movement_lineage_delete_votes`
+
+Curator votes requesting deletion of a lineage link. Only **admins** may hard-delete the link. Migration: `db/migrate-movement-link-delete-votes.sql`.
+
+| Column | Type | Notes |
+|--------|------|-------|
+| `id` | SERIAL PK | |
+| `link_id` | FK → `movement_lineage_links` | Cascade on link delete |
+| `user_id` | FK → `users` | One vote per user per link |
+| `reason` | TEXT NOT NULL | Min 10 characters (trimmed) |
+| `created_at` | TIMESTAMPTZ | |
+
 ### `users`
 
 Staff accounts (named logins). Anonymous site visitors do not have rows here. Migration: `db/migrate-auth.sql` + `db/migrate-user-roles.sql`.

Documentation/FAC.md

@@ -95,7 +95,7 @@ CURATOR_USERNAME=curator
 CURATOR_PASSWORD=your-secure-password
 ```
 
-Then open the gallery → **Curator login** (top-right) → use tools allowed by your role/permissions (debug, Checkup, Translations, Influences, Tour editor, **Users**, **Activity**). Mutations are logged in `curator_audit_log` per user.
+Then open the gallery → **Curator login** (top-right) → use tools allowed by your role/permissions (debug, Checkup, Translations, Influences, **Movement links** top-left, Tour editor, **Users**, **Activity**). Mutations are logged in `curator_audit_log` per user.
 
 If login fails after changing `CURATOR_PASSWORD` in `.env`, run `npm run dev:reset-curator` (bootstrap only runs when `users` is empty; reset upserts the env account as **admin**).
 
@@ -103,9 +103,9 @@ If login fails after changing `CURATOR_PASSWORD` in `.env`, run `npm run dev:res
 
 | Role | Access |
 |------|--------|
-| Guest (`user`) | Timeline, movement flow, 3D halls, painting detail, bios |
+| Guest (`user`) | Timeline, movement flow, 3D halls, painting detail, bios; can open **Movement links** login gate |
-| Curator | Public browse + assigned permission flags (`images`, `checkup`, `curator_notes`, `translations`, `influences`, `tours`, `users`) |
+| Curator | Public browse + assigned permission flags (`images`, `checkup`, `curator_notes`, `translations`, `influences`, `tours`, `users`). With `influences`: Influences + Movement links create/vote-to-delete |
-| Admin | All curator tools + **Users** + **Activity** audit reports |
+| Admin | All curator tools + **Users** + **Activity** + hard-delete movement links |
 
 **Users page:** after admin login, header → **Users** — create/edit staff, reset passwords, disable accounts. Prod and dev keep **separate** `users` tables: `devtoprod:db:restore` and harmonize never copy staff accounts. If create fails with a confusing “already exists” after a restore, serial sequences may be lagging — current restore syncs them to `MAX(id)`, and user create re-syncs `users_id_seq` before insert.
 

Documentation/Plans.md

@@ -18,4 +18,5 @@ this file contains draft for future releases and features
 9. ~~vertical bottom-up timeline (alternative start page)~~ — done: `VerticalTimeline` + `VerticalMovementBands`, header layout switch — [basics.md](basics.md#timeline-and-movement-flow)
 10. ~~Tree of Art timeline (lineage as a growing tree)~~ — done: `MovementTree` + `movementTree.ts`, shareable `?layout=tree` — [movement-tree.md](movement-tree.md)
 11. ~~UI interaction and component standards~~ — done: shared doc + Cursor rule for client screens — [ui-interaction-and-component-standards.md](ui-interaction-and-component-standards.md)
+12. ~~Movement lineage curator config (links + proof URLs + delete votes)~~ — done: `movement_lineage_links` / `movement_lineage_delete_votes`, `MovementLinksPage`, admin-only hard delete — [data-and-images.md](data-and-images.md#movement-lineage-timeline--tree-of-art) / [API.md](API.md#movement-lineage-links)
 

Documentation/basics.md

@@ -56,6 +56,7 @@ Gallery/
 │   │   ├── pages/CheckupPage.tsx            # Image audit table
 │   │   ├── pages/TranslationsPage.tsx       # Russian translation review
 │   │   ├── pages/InfluencesPage.tsx         # Influence links CRUD + import wizard
+│   │   ├── pages/MovementLinksPage.tsx      # Movement lineage CRUD + delete votes
 │   │   ├── pages/ToursPage.tsx              # Guided tour editor
 │   │   ├── pages/UsersPage.tsx              # Staff accounts
 │   │   ├── pages/AuditPage.tsx              # Admin curator activity reports
@@ -63,7 +64,7 @@ Gallery/
 │   │   ├── i18n/                            # react-i18next bootstrap
 │   │   ├── locales/{en,ru}/                 # UI chrome strings (incl. timeline layout + captions)
 │   │   ├── data/historical-events.ts     # Timeline event markers (UI)
-│   │   ├── data/movement-lineage.ts       # Curated movement predecessor links (UI)
+│   │   ├── data/movement-lineage.ts       # Fallback movement predecessor links (UI)
 │   │   ├── utils/parquetFloorTexture.ts     # Procedural parquet floor
 │   │   ├── utils/debugMode.ts               # Debug mode + “Show more” localStorage prefs
 │   │   ├── utils/timelineView.ts          # Shared zoom/pan math for timeline + movements
@@ -263,7 +264,7 @@ Each visible movement is drawn as a **portrait-width curved stream** (~54 px str
 
 | Feature | Implementation |
 |---------|----------------|
-| Lineage layout | `client/src/data/movement-lineage.ts` — curated predecessor→successor pairs (Met / ArtStory / museum essays); multiple parents allowed |
+| Lineage layout | `movement_lineage_links` (DB) via `GET /api/movement-links`; client fallback `movement-lineage.ts`; **Movement links** page (top-left header control; create/vote needs `influences`; hard delete is **admin-only**); multiple parents allowed |
 | Vertical lanes | Movements share a horizontal lane only when one ends at least **10 years** before the next starts (in the current zoom); closer or overlapping spans stack into extra rows (`assignTemporalLanes`). Lane choice **minimizes vertical branch length**: children prefer parent lanes (same row when years allow), corridor clearing (up to 20 passes) evicts unrelated streams preferring **rows above** the parent/child strip, then re-attracts the child toward the parent |
 | Branch connectors | Smooth curves from fan-out points along a parent stream to the **left edge (start)** of each child stream; origin X is always strictly left of the target (time-forward only — never right→left); stroke thickness matches the **target** (child) band height; color gradients from parent → child at constant opacity; a stream-shaped mask hides branch ink under movements so translucent overlaps do not brighten the bands; pan/zoom layout changes **animate** (streams + branches chase new geometry) so shifts stay trackable |
 | Band thickness | Stream height is **proportional to `influence_link_count`** (edges on paintings by artists in that movement): thicker bands for denser influence graphs; lane rows share vertical space weighted by the thickest band in each lane |
@@ -296,7 +297,7 @@ Each artist appears as a **portrait circle** on their movement’s stream row:
 
 Only **mousedown** on portraits and movement labels stops propagation (so drag-to-pan does not start when clicking them). Hovering a portrait highlights the artist’s lifespan on the era bar and brightens their segment on the movement stream.
 
-**Note:** Movement lineage is **frontend curation** for layout and labels — it is not stored in PostgreSQL. Painting influence links live in **`painting_influence_sources`** (paintings, artists, or movements as sources). The API reads that table for detail panels, hall navigation, and `has_influence_links`. The legacy **`painting_influences`** table is still written in parallel when curators add painting-to-painting edges but is not queried for display.
+**Note:** Movement lineage lives in **`movement_lineage_links`** (source/target movements, approx year, required `proof_url`). Timeline / Tree of Art load it from `GET /api/movement-links` (static fallback in `movement-lineage.ts` if the API is empty). Curators with `influences` can add links and **vote to delete** (with reason); only **admins** hard-delete. Votes are stored in `movement_lineage_delete_votes`. Painting influence links live in **`painting_influence_sources`** (paintings, artists, or movements as sources). The API reads that table for detail panels, hall navigation, and `has_influence_links`. The legacy **`painting_influences`** table is still written in parallel when curators add painting-to-painting edges but is not queried for display.
 
 ## Virtual gallery (3D halls)
 
@@ -459,7 +460,7 @@ Next to the toggle, **Show more** (checkbox, persisted in `localStorage`) opens
 - **Timeline catalog** loads once from the API; pan/zoom is client-side only, with per-frame batching via `createViewChangeScheduler()`.
 - **Movement flow interaction** uses simplified SVG and hides portrait DOM during active scroll/drag so zoom stays responsive over dense portrait fields.
 - **Movement filtering** on zoom shows movements whose span overlaps the visible year range and that have at least one catalogued artist; a movement (e.g. Byzantine or Gothic viewed at 311–1231 CE) still appears even when all its artists lived outside the current window.
-- **Movement lineage** (`movement-lineage.ts`) documents art-historical predecessor→successor links for the flow diagram; extend that file to add or correct branches.
+- **Movement lineage** — top-left **Movement links** opens `MovementLinksPage` (login if needed). Create requires `influences` + proof URL; curators vote to delete with a reason; admins review votes and delete. Data: `movement_lineage_links` / `movement_lineage_delete_votes`; timeline uses `GET /api/movement-links` with fallback `movement-lineage.ts`. After code changes that affect the SPA on port `3451`, run `npm run build --prefix client` (that port serves `client/dist`).
 - **One hall per artist** keeps navigation predictable: enter from the timeline or bio, leave via the single exit or back button.
 - **Movement galleries** complement artist halls: full movement corpus in period-themed wings, entered from the flow diagram.
 - **Guided tours** add curator-ordered winged halls with stop text on painting detail — [tours.md](tours.md).

Documentation/data-and-images.md

@@ -263,18 +263,23 @@ Discovered rows are stored with `confidence: discovered` and `discovered_via` (e
 
 Extend `art-influences-data.js` for high-quality curated chains; use discovery to suggest additional artist and movement links for manual review.
 
-## Movement lineage (frontend flow diagram)
+## Movement lineage (timeline / Tree of Art)
 
-Separate from the painting influence graph, `client/src/data/movement-lineage.ts` lists **art-movement** predecessor→successor pairs used only by `MovementBands.tsx` to position streams and draw branch connectors (e.g. Impressionism → Post-Impressionism → Fauvism / Cubism / Expressionism).
+Separate from the painting influence graph, **`movement_lineage_links`** stores art-movement predecessor→successor pairs used by `MovementBands`, `VerticalMovementBands`, and `MovementTree` (e.g. Impressionism → Post-Impressionism → Fauvism / Cubism / Expressionism).
 
 | Aspect | Detail |
 |--------|--------|
-| Storage | TypeScript module in the client — **not** a database table |
+| Storage | PostgreSQL `movement_lineage_links` (`db/migrate-movement-links.sql`) |
-| Format | `[parentMovementName, childMovementName]` tuples; names must match `art_movements.name` from the seed |
+| Required proof | `proof_url` must be a valid `http(s)` URL (museum essay, literature, web reference) |
-| Multiple parents | Allowed (e.g. Post-Impressionism feeding several modern paths) |
+| Optional | `link_year_approx`, `proof_label`, `notes` |
-| Sources | Curator notes in the file reference Met essays, TheArtStory, and similar |
+| Format | FK pairs to `art_movements`; multiple parents allowed |
+| API | Public `GET /api/movement-links`; curator `POST` create + delete votes; **admin-only** hard `DELETE` |
+| UI | Top-left **Movement links** (timeline header); also linked from Influences. Curators create + vote-to-delete (reason); admins review votes and hard-delete |
+| Fallback | `client/src/data/movement-lineage.ts` if the API returns no rows |
+| Defaults | Seeded on migrate / first GET from Met / TheArtStory / Christie's essays |
+| Delete votes | `movement_lineage_delete_votes` (`db/migrate-movement-link-delete-votes.sql`); one vote per curator per link |
 
-To add or fix a branch, edit `MOVEMENT_LINEAGE` in that file and rebuild the client. No migration or API change is required.
+To add a branch, use **Movement links** (proof URL required). To remove one, curators vote with a reason; an admin deletes after review. No client rebuild is required for data changes; rebuild `client/dist` only when shipping SPA changes to the API-static port (`3451` / prod).
 
 ## Movement gallery interiors (frontend)
 

Documentation/influence-import.md

@@ -82,6 +82,23 @@ Audit: `influence.create` / `update` / `delete` / `import` in `curator_audit_log
 
 ---
 
+## Movement lineage links (related curator tool)
+
+Top-left timeline control **Movement links** (also from Influences → **Movement links →**). Create/vote need `influences`; hard delete is **admin-only**. Tables `movement_lineage_links` + `movement_lineage_delete_votes`.
+
+| Method | Path | Purpose |
+|--------|------|---------|
+| `GET` | `/api/movement-links` | Public list (timeline / tree); includes `delete_vote_count` |
+| `POST` | `/api/movement-links` | Create (`sourceMovementId`, `targetMovementId`, `proofUrl` required) |
+| `POST` | `/api/movement-links/:id/delete-votes` | Curator vote to delete (`reason` required, min 10 chars) |
+| `GET` | `/api/movement-links/:id/delete-votes` | List votes (username + reason) for admin review |
+| `DELETE` | `/api/movement-links/:id/delete-votes/me` | Withdraw own vote |
+| `DELETE` | `/api/movement-links/:id` | **Admin only** — hard delete |
+
+See [data-and-images.md](data-and-images.md#movement-lineage-timeline--tree-of-art).
+
+---
+
 ## CLI still available
 
 - `npm run dev:update-influences` — curated [`scripts/art-influences-data.js`](../scripts/art-influences-data.js)

Documentation/movement-tree.md

@@ -102,6 +102,8 @@ All constants sit at the top of the two files and are safe to tune:
 | `FULL_VIEW_WIDTH_SHARE`, `ZOOM_SPREAD_EXPONENT`, `MAX_FIT_BOOST` | `MovementTree.tsx` | crown spread vs. zoom |
 | `MIN_LIMB_RISE_PX`, `MIN_JUNCTION_RISE_PX`, `MAX_THICKNESS_OF_LENGTH` | `MovementTree.tsx` | crown legibility at full zoom-out |
 
-New lineage edges only need adding to
+New lineage edges: top-left **Movement links** (required proof URL) →
-[`client/src/data/movement-lineage.ts`](../client/src/data/movement-lineage.ts) — the tree
+`movement_lineage_links` / `GET /api/movement-links`. Curators vote to delete;
-picks up parents, grafts, thickness and spacing from there automatically.
+admins hard-delete. Static fallback remains in
+[`client/src/data/movement-lineage.ts`](../client/src/data/movement-lineage.ts).
+The tree picks up parents, grafts, thickness and spacing from the active lineage automatically.

Documentation/setup.md

@@ -72,7 +72,7 @@ If migration fails with permission errors, grant schema rights to the app user f
 
 `npm run dev:migrate` applies `db/migrate-auth.sql` (`users`, `curator_audit_log`, `session` tables). When the `users` table is empty and `CURATOR_USERNAME` / `CURATOR_PASSWORD` are set in `.env`, the first curator account is created automatically. To sync the password from `.env` later, run `npm run dev:reset-curator`.
 
-After migrate, sign in from the site header (**Curator login**). Debug mode, Checkup, Translations, Influences, Tour editor, and all mutating debug APIs require an active curator session. Anonymous visitors browse the timeline, published Tours, and 3D halls without logging in.
+After migrate, sign in from the site header (**Curator login**). Debug mode, Checkup, Translations, Influences, **Movement links** (top-left), Tour editor, and all mutating debug APIs require an active curator session (Movement links opens a login gate for guests). Anonymous visitors browse the timeline, published Tours, and 3D halls without logging in. `dev:migrate` also creates `movement_lineage_links` / `movement_lineage_delete_votes` and seeds default lineage when the table is empty.
 
 See [API.md — Authentication](API.md#authentication) and [basics.md — Developer tools](basics.md#developer-tools-image-audit).
 

client/src/api/client.ts

@@ -773,6 +773,81 @@ export const api = {
     );
   },
 
+  listMovementLinks: (params: { q?: string; limit?: number; offset?: number } = {}) => {
+    const qs = new URLSearchParams();
+    if (params.q) qs.set('q', params.q);
+    if (params.limit) qs.set('limit', String(params.limit));
+    if (params.offset) qs.set('offset', String(params.offset));
+    const q = qs.toString();
+    return fetchJson<{ items: MovementLineageLinkItem[]; total: number }>(
+      `${API}/movement-links${q ? `?${q}` : ''}`,
+    );
+  },
+
+  createMovementLink: (payload: {
+    sourceMovementId: number;
+    targetMovementId: number;
+    proofUrl: string;
+    proofLabel?: string;
+    linkYearApprox?: number | null;
+    notes?: string;
+  }) =>
+    fetch(`${API}/movement-links`, {
+      ...fetchCredentials,
+      method: 'POST',
+      headers: { 'Content-Type': 'application/json' },
+      body: JSON.stringify(payload),
+    }).then(async (res) => {
+      if (!res.ok) {
+        const body = await res.json().catch(() => ({}));
+        throw new Error(body.error || `Create failed: ${res.status}`);
+      }
+      return res.json() as Promise<{ item: MovementLineageLinkItem }>;
+    }),
+
+  listMovementLinkDeleteVotes: (id: number) =>
+    fetchJson<{ linkId: number; votes: MovementLineageDeleteVote[] }>(
+      `${API}/movement-links/${id}/delete-votes`,
+    ),
+
+  voteDeleteMovementLink: (id: number, reason: string) =>
+    fetch(`${API}/movement-links/${id}/delete-votes`, {
+      ...fetchCredentials,
+      method: 'POST',
+      headers: { 'Content-Type': 'application/json' },
+      body: JSON.stringify({ reason }),
+    }).then(async (res) => {
+      if (!res.ok) {
+        const body = await res.json().catch(() => ({}));
+        throw new Error(body.error || `Vote failed: ${res.status}`);
+      }
+      return res.json() as Promise<{ vote: MovementLineageDeleteVote }>;
+    }),
+
+  withdrawDeleteMovementLinkVote: (id: number) =>
+    fetch(`${API}/movement-links/${id}/delete-votes/me`, {
+      ...fetchCredentials,
+      method: 'DELETE',
+    }).then(async (res) => {
+      if (!res.ok) {
+        const body = await res.json().catch(() => ({}));
+        throw new Error(body.error || `Withdraw failed: ${res.status}`);
+      }
+      return res.json() as Promise<{ ok: boolean; id: number; linkId: number }>;
+    }),
+
+  deleteMovementLink: (id: number) =>
+    fetch(`${API}/movement-links/${id}`, {
+      ...fetchCredentials,
+      method: 'DELETE',
+    }).then(async (res) => {
+      if (!res.ok) {
+        const body = await res.json().catch(() => ({}));
+        throw new Error(body.error || `Delete failed: ${res.status}`);
+      }
+      return res.json() as Promise<{ ok: boolean; id: number }>;
+    }),
+
   getInfluenceGraph: (params: { artistId?: number; paintingId?: number }) => {
     const qs = new URLSearchParams();
     if (params.artistId) qs.set('artistId', String(params.artistId));
@@ -1032,6 +1107,33 @@ export interface InfluenceEdgeItem {
   updatedAt: string | null;
 }
 
+export interface MovementLineageLinkItem {
+  id: number;
+  source_movement_id: number;
+  target_movement_id: number;
+  link_year_approx: number | null;
+  proof_url: string;
+  proof_label: string | null;
+  notes: string | null;
+  created_at: string;
+  updated_at: string;
+  source_name: string;
+  source_start_year: number;
+  target_name: string;
+  target_start_year: number;
+  delete_vote_count?: number;
+  viewer_has_delete_vote?: boolean;
+}
+
+export interface MovementLineageDeleteVote {
+  id: number;
+  link_id: number;
+  user_id: number;
+  reason: string;
+  created_at: string;
+  username?: string;
+}
+
 export interface InfluenceGraph {
   focus: { artistId: number; paintingId: number | null; label: string };
   nodes: Array<{ id: string; type: string; label: string; focus?: boolean; artistId?: number; paintingId?: number; movementId?: number }>;

client/src/components/MovementBands.tsx

@@ -3,7 +3,7 @@ import { useTranslation } from 'react-i18next';
 import type { ArtMovement, Artist } from '../types';
 import { portraitThumbUrl } from '../api/client';
 import { useQueuedImageSrc } from '../hooks/useQueuedImageSrc';
-import { MOVEMENT_LINEAGE } from '../data/movement-lineage';
+import { getMovementLineage } from '../data/movement-lineage';
 import { panTimelineView, zoomTimelineView } from '../utils/timelineView';
 import { parseHexColor, rgbToHsl, hslToHex, vividMovementColor } from '../utils/movementColor';
 import './MovementBands.css';
@@ -269,7 +269,7 @@ function buildLineageParentMap(
   const visibleIds = new Set(visible.map((m) => m.id));
   const childToParents = new Map<number, number[]>();
 
-  for (const [parentName, childName] of MOVEMENT_LINEAGE) {
+  for (const [parentName, childName] of getMovementLineage()) {
     const parentId = nameToId.get(parentName);
     const childId = nameToId.get(childName);
     if (!parentId || !childId) continue;

client/src/components/VerticalMovementBands.tsx

@@ -1,7 +1,7 @@
 import { useMemo, useRef, useCallback, useEffect, useLayoutEffect, useState } from 'react';
 import { useTranslation } from 'react-i18next';
 import type { ArtMovement } from '../types';
-import { MOVEMENT_LINEAGE } from '../data/movement-lineage';
+import { getMovementLineage } from '../data/movement-lineage';
 import { panTimelineView, zoomTimelineView } from '../utils/timelineView';
 import { vividMovementColor } from '../utils/movementColor';
 import './VerticalMovementBands.css';
@@ -59,7 +59,7 @@ function buildLineageParentMap(
 ): Map<number, number[]> {
   const parents = new Map<number, number[]>();
   const visibleIds = new Set(visible.map((m) => m.id));
-  for (const [parentName, childName] of MOVEMENT_LINEAGE) {
+  for (const [parentName, childName] of getMovementLineage()) {
     const parentId = nameToId.get(parentName);
     const childId = nameToId.get(childName);
     if (parentId == null || childId == null) continue;

client/src/data/movement-lineage.ts

@@ -1,10 +1,12 @@
 /**
- * Documented art-historical movement lineage (predecessor → successor).
+ * Art-historical movement lineage (predecessor → successor).
- * Sources: Met Museum essays, TheArtStory, Sotheby's movement guides.
+ * Defaults match museum essays; live data comes from GET /api/movement-links.
- *
  * Multiple parents are allowed (e.g. Post-Impressionism feeding several modern paths).
  */
-export const MOVEMENT_LINEAGE: ReadonlyArray<readonly [parent: string, child: string]> = [
+
+export type MovementLineageEdge = readonly [parent: string, child: string];
+
+export const FALLBACK_MOVEMENT_LINEAGE: ReadonlyArray<MovementLineageEdge> = [
   // Classical & medieval
   ['Ancient Greek & Roman', 'Byzantine'],
   ['Byzantine', 'Gothic'],
@@ -21,17 +23,17 @@ export const MOVEMENT_LINEAGE: ReadonlyArray<readonly [parent: string, child: st
   ['Rococo', 'Neoclassicism'],
   ['Neoclassicism', 'Romanticism'],
   ['Romanticism', 'Realism'],
-  ['Romanticism', 'Impressionism'], // Turner, Delacroix → light and atmosphere
+  ['Romanticism', 'Impressionism'],
   ['Realism', 'Impressionism'],
 
-  // Modern origins (Met / ArtStory: Impressionism → Post-Impressionism → …)
+  // Modern origins
   ['Impressionism', 'Post-Impressionism'],
   ['Post-Impressionism', 'Symbolism'],
   ['Post-Impressionism', 'Fauvism'],
   ['Post-Impressionism', 'Expressionism'],
-  ['Post-Impressionism', 'Cubism'], // Cézanne's structure → Picasso/Braque
+  ['Post-Impressionism', 'Cubism'],
   ['Symbolism', 'Art Nouveau'],
-  ['Fauvism', 'Cubism'], // Braque, Matisse → geometric turn
+  ['Fauvism', 'Cubism'],
   ['Cubism', 'Futurism'],
   ['Cubism', 'Suprematism'],
   ['Cubism', 'Constructivism'],
@@ -43,10 +45,35 @@ export const MOVEMENT_LINEAGE: ReadonlyArray<readonly [parent: string, child: st
   ['Abstract Expressionism', 'Pop Art'],
 ];
 
+let activeLineage: ReadonlyArray<MovementLineageEdge> = FALLBACK_MOVEMENT_LINEAGE;
+
+/** Active edges for timeline / tree layout (API-backed when loaded). */
+export function getMovementLineage(): ReadonlyArray<MovementLineageEdge> {
+  return activeLineage;
+}
+
+/** Apply curator DB rows; empty list keeps the static fallback. */
+export function setMovementLineageFromApi(
+  items: ReadonlyArray<{ source_name: string; target_name: string }>
+): void {
+  if (!items.length) {
+    activeLineage = FALLBACK_MOVEMENT_LINEAGE;
+    return;
+  }
+  activeLineage = items.map((row) => [row.source_name, row.target_name] as const);
+}
+
+/** @deprecated Use getMovementLineage() — alias for older imports. */
+export const MOVEMENT_LINEAGE = FALLBACK_MOVEMENT_LINEAGE;
+
 export function lineageParentsByName(childName: string): string[] {
-  return MOVEMENT_LINEAGE.filter(([, child]) => child === childName).map(([parent]) => parent);
+  return getMovementLineage()
+    .filter(([, child]) => child === childName)
+    .map(([parent]) => parent);
 }
 
 export function lineageChildrenByName(parentName: string): string[] {
-  return MOVEMENT_LINEAGE.filter(([parent]) => parent === parentName).map(([, child]) => child);
+  return getMovementLineage()
+    .filter(([parent]) => parent === parentName)
+    .map(([, child]) => child);
 }

client/src/i18n/index.ts

@@ -12,6 +12,7 @@ import enAnnotations from '../locales/en/annotations.json';
 import enDebug from '../locales/en/debug.json';
 import enTranslations from '../locales/en/translations.json';
 import enInfluences from '../locales/en/influences.json';
+import enMovementLinks from '../locales/en/movementLinks.json';
 import enTours from '../locales/en/tours.json';
 import enUsers from '../locales/en/users.json';
 import enAudit from '../locales/en/audit.json';
@@ -26,6 +27,7 @@ import ruAnnotations from '../locales/ru/annotations.json';
 import ruDebug from '../locales/ru/debug.json';
 import ruTranslations from '../locales/ru/translations.json';
 import ruInfluences from '../locales/ru/influences.json';
+import ruMovementLinks from '../locales/ru/movementLinks.json';
 import ruTours from '../locales/ru/tours.json';
 import ruUsers from '../locales/ru/users.json';
 import ruAudit from '../locales/ru/audit.json';
@@ -37,7 +39,7 @@ void i18n.use(initReactI18next).init({
   lng: initialLocale,
   fallbackLng: 'en',
   supportedLngs: ['en', 'ru'],
-  ns: ['common', 'home', 'search', 'gallery', 'painting', 'bio', 'annotations', 'debug', 'translations', 'influences', 'tours', 'users', 'audit'],
+  ns: ['common', 'home', 'search', 'gallery', 'painting', 'bio', 'annotations', 'debug', 'translations', 'influences', 'movementLinks', 'tours', 'users', 'audit'],
   defaultNS: 'common',
   resources: {
     en: {
@@ -51,6 +53,7 @@ void i18n.use(initReactI18next).init({
       debug: enDebug,
       translations: enTranslations,
       influences: enInfluences,
+      movementLinks: enMovementLinks,
       tours: enTours,
       users: enUsers,
       audit: enAudit,
@@ -66,6 +69,7 @@ void i18n.use(initReactI18next).init({
       debug: ruDebug,
       translations: ruTranslations,
       influences: ruInfluences,
+      movementLinks: ruMovementLinks,
       tours: ruTours,
       users: ruUsers,
       audit: ruAudit,

client/src/locales/en/home.json

@@ -15,6 +15,7 @@
   "checkup": "Checkup",
   "translations": "Translations",
   "influences": "Influences",
+  "movementLinks": "Movement links",
   "tours": "Tours",
   "toursEditor": "Tour editor",
   "users": "Users",

client/src/locales/en/influences.json

@@ -1,6 +1,7 @@
 {
   "title": "Influence links",
   "back": "← Back to gallery",
+  "openMovementLinks": "Movement links →",
   "tabList": "List",
   "tabImport": "Import",
   "tabGraph": "Graph",

client/src/locales/en/movementLinks.json

@@ -0,0 +1,52 @@
+{
+  "title": "Movement links",
+  "back": "← Back to gallery",
+  "intro": "Predecessor → successor edges used by the timeline flow and Tree of Art. Every link needs a proof URL (museum essay, literature, or other web reference).",
+  "introCurator": "Curators can vote to delete a link and must give a reason. Only an admin can perform the final delete after reviewing votes.",
+  "introAdmin": "As admin you can delete links directly. Review curator delete votes (reasons) before confirming.",
+  "loadFailed": "Failed to load movement links",
+  "saveFailed": "Failed to save movement link",
+  "deleteFailed": "Failed to delete movement link",
+  "voteFailed": "Failed to cast delete vote",
+  "withdrawFailed": "Failed to withdraw vote",
+  "searchPlaceholder": "Search source, target, proof…",
+  "refresh": "Refresh",
+  "loading": "Loading…",
+  "loadingVotes": "Loading votes…",
+  "votesLoadFailed": "Could not load votes.",
+  "total": "{{count}} links",
+  "noLinks": "No movement links yet.",
+  "addLink": "Add link",
+  "cancelAdd": "Cancel",
+  "addTitle": "New movement link",
+  "source": "Source (from)",
+  "target": "Target (to)",
+  "pickMovement": "Select movement…",
+  "proofUrl": "Proof URL",
+  "proofLabel": "Proof label",
+  "proofLabelPlaceholder": "e.g. Met — Cubism",
+  "linkYear": "Link date ≈",
+  "linkYearPlaceholder": "e.g. 1907",
+  "notes": "Notes",
+  "saveLink": "Save link",
+  "saving": "Saving…",
+  "addRequiresMovements": "Pick both source and target movements",
+  "proofRequired": "Proof URL is required",
+  "voteTitle": "Vote to delete",
+  "voteReason": "Reason",
+  "voteReasonPlaceholder": "Explain why this link should be removed (min. 10 characters)…",
+  "voteReasonRequired": "Reason must be at least 10 characters",
+  "submitVote": "Submit vote",
+  "cancelVote": "Cancel",
+  "voteDelete": "Vote to delete",
+  "withdrawVote": "Withdraw vote",
+  "voteCount": "{{count}} vote(s)",
+  "colSource": "Source",
+  "colTarget": "Target",
+  "colYear": "Link date ≈",
+  "colProof": "Reference / proof",
+  "colVotes": "Delete votes",
+  "colActions": "Actions",
+  "delete": "Delete",
+  "confirmDelete": "Delete this movement link? Curator vote reasons will be recorded in the audit log."
+}

client/src/locales/en/users.json

@@ -25,7 +25,7 @@
   "perm_checkup": "Checkup",
   "perm_curator_notes": "Curator notes",
   "perm_translations": "Translations",
-  "perm_influences": "Influences",
+  "perm_influences": "Influences & movement links",
   "perm_tours": "Tours",
   "perm_users": "Users",
   "adminAllPerms": "Admins have all permissions automatically.",

client/src/locales/ru/home.json

@@ -15,6 +15,7 @@
   "checkup": "Проверка",
   "translations": "Переводы",
   "influences": "Влияния",
+  "movementLinks": "Связи движений",
   "tours": "Экскурсии",
   "toursEditor": "Редактор экскурсий",
   "users": "Пользователи",

client/src/locales/ru/influences.json

@@ -1,6 +1,7 @@
 {
   "title": "Связи влияния",
   "back": "← Назад в галерею",
+  "openMovementLinks": "Связи движений →",
   "tabList": "Список",
   "tabImport": "Импорт",
   "tabGraph": "Граф",

client/src/locales/ru/movementLinks.json

@@ -0,0 +1,52 @@
+{
+  "title": "Связи движений",
+  "back": "← Назад в галерею",
+  "intro": "Связи предшественник → преемник для ленты и «Дерева искусства». Для каждой связи нужна ссылка-доказательство (музейный очерк, литература или интернет).",
+  "introCurator": "Кураторы могут голосовать за удаление связи с указанием причины. Окончательное удаление выполняет только администратор после просмотра голосов.",
+  "introAdmin": "Как администратор вы можете удалять связи напрямую. Перед подтверждением просмотрите голоса кураторов и их причины.",
+  "loadFailed": "Не удалось загрузить связи движений",
+  "saveFailed": "Не удалось сохранить связь",
+  "deleteFailed": "Не удалось удалить связь",
+  "voteFailed": "Не удалось отправить голос",
+  "withdrawFailed": "Не удалось отозвать голос",
+  "searchPlaceholder": "Поиск: источник, цель, ссылка…",
+  "refresh": "Обновить",
+  "loading": "Загрузка…",
+  "loadingVotes": "Загрузка голосов…",
+  "votesLoadFailed": "Не удалось загрузить голоса.",
+  "total": "{{count}} связей",
+  "noLinks": "Связей движений пока нет.",
+  "addLink": "Добавить связь",
+  "cancelAdd": "Отмена",
+  "addTitle": "Новая связь движений",
+  "source": "Источник (от)",
+  "target": "Цель (к)",
+  "pickMovement": "Выберите движение…",
+  "proofUrl": "Ссылка-доказательство",
+  "proofLabel": "Подпись ссылки",
+  "proofLabelPlaceholder": "напр. Met — Cubism",
+  "linkYear": "Дата связи ≈",
+  "linkYearPlaceholder": "напр. 1907",
+  "notes": "Заметки",
+  "saveLink": "Сохранить",
+  "saving": "Сохранение…",
+  "addRequiresMovements": "Выберите исходное и целевое движение",
+  "proofRequired": "Ссылка-доказательство обязательна",
+  "voteTitle": "Голос за удаление",
+  "voteReason": "Причина",
+  "voteReasonPlaceholder": "Почему связь нужно удалить (мин. 10 символов)…",
+  "voteReasonRequired": "Причина должна быть не короче 10 символов",
+  "submitVote": "Отправить голос",
+  "cancelVote": "Отмена",
+  "voteDelete": "Голосовать за удаление",
+  "withdrawVote": "Отозвать голос",
+  "voteCount": "{{count}} голос(ов)",
+  "colSource": "Источник",
+  "colTarget": "Цель",
+  "colYear": "Дата ≈",
+  "colProof": "Ссылка / доказательство",
+  "colVotes": "Голоса за удаление",
+  "colActions": "Действия",
+  "delete": "Удалить",
+  "confirmDelete": "Удалить эту связь движений? Причины голосов кураторов будут записаны в журнал аудита."
+}

client/src/locales/ru/users.json

@@ -25,7 +25,7 @@
   "perm_checkup": "Проверка",
   "perm_curator_notes": "Заметки куратора",
   "perm_translations": "Переводы",
-  "perm_influences": "Влияния",
+  "perm_influences": "Влияния и связи движений",
   "perm_tours": "Экскурсии",
   "perm_users": "Пользователи",
   "adminAllPerms": "У администраторов все права автоматически.",

client/src/pages/HomePage.css

@@ -116,8 +116,12 @@
   top: 16px;
   right: 16px;
   display: flex;
+  flex-wrap: wrap;
+  justify-content: flex-end;
   gap: 8px;
   align-items: center;
+  max-width: min(780px, calc(100vw - 24px));
+  z-index: 120;
 }
 
 .debug-mode-toggle,

client/src/pages/HomePage.tsx

@@ -12,6 +12,7 @@ import ArtistBio from '../components/ArtistBio';
 import CheckupPage from '../pages/CheckupPage';
 import TranslationsPage from '../pages/TranslationsPage';
 import InfluencesPage from '../pages/InfluencesPage';
+import MovementLinksPage from '../pages/MovementLinksPage';
 import ToursPage from '../pages/ToursPage';
 import UsersPage from '../pages/UsersPage';
 import AuditPage from '../pages/AuditPage';
@@ -28,11 +29,13 @@ import '../components/ToursPopup.css';
 import '../components/LocaleSwitcher.css';
 import '../pages/TranslationsPage.css';
 import '../pages/InfluencesPage.css';
+import '../pages/MovementLinksPage.css';
 import '../pages/ToursPage.css';
 import '../pages/UsersPage.css';
 import '../pages/AuditPage.css';
 import { useAuth } from '../context/AuthContext';
 import { api, setApiLocale, type FixPaintingImageResult, type FixArtistPortraitResult } from '../api/client';
+import { setMovementLineageFromApi } from '../data/movement-lineage';
 import type {
   TimelineData,
   Artist,
@@ -55,6 +58,7 @@ type View =
   | { type: 'checkup' }
   | { type: 'translations' }
   | { type: 'influences' }
+  | { type: 'movement-links' }
   | { type: 'tours' }
   | { type: 'users' }
   | { type: 'audit' }
@@ -69,7 +73,7 @@ type GallerySession =
   | { kind: 'movement'; movementId: number; data: MovementGalleryDetail }
   | { kind: 'tour'; tourId: number; data: TourGalleryDetail };
 
-type CuratorLoginRedirect = 'checkup' | 'translations' | 'influences' | 'tours' | 'users' | 'audit' | null;
+type CuratorLoginRedirect = 'checkup' | 'translations' | 'influences' | 'movement-links' | 'tours' | 'users' | 'audit' | null;
 
 function patchPaintingInMovementDetail(
   detail: MovementGalleryDetail,
@@ -259,9 +263,14 @@ export default function HomePage() {
     (async () => {
       try {
         setLoading(true);
-        const catalog = await api.getCatalogBootstrap();
+        const [catalog, lineage] = await Promise.all([
+          api.getCatalogBootstrap(),
+          api.listMovementLinks({ limit: 500 }).catch(() => ({ items: [] as Awaited<ReturnType<typeof api.listMovementLinks>>['items'] })),
+        ]);
         if (cancelled) return;
 
+        setMovementLineageFromApi(lineage.items);
+
         const min = catalog.bounds.min_year ?? -800;
         const max = catalog.bounds.max_year ?? 2025;
         setBounds({ min, max });
@@ -363,6 +372,8 @@ export default function HomePage() {
       setView({ type: 'translations' });
     } else if (loginRedirect === 'influences') {
       setView({ type: 'influences' });
+    } else if (loginRedirect === 'movement-links') {
+      setView({ type: 'movement-links' });
     } else if (loginRedirect === 'tours') {
       setView({ type: 'tours' });
     } else if (loginRedirect === 'users') {
@@ -381,6 +392,7 @@ export default function HomePage() {
       view.type === 'checkup' ||
       view.type === 'translations' ||
       view.type === 'influences' ||
+      view.type === 'movement-links' ||
       view.type === 'tours' ||
       view.type === 'users' ||
       view.type === 'audit'
@@ -413,6 +425,14 @@ export default function HomePage() {
     setView({ type: 'influences' });
   };
 
+  const openMovementLinks = () => {
+    if (!canInfluences) {
+      openCuratorLogin('movement-links');
+      return;
+    }
+    setView({ type: 'movement-links' });
+  };
+
   const openToursEditor = () => {
     if (!canTours) {
       openCuratorLogin('tours');
@@ -1128,7 +1148,7 @@ export default function HomePage() {
 
       {view.type === 'influences' && (
         canInfluences ? (
-          <InfluencesPage onBack={goToTimelineHome} />
+          <InfluencesPage onBack={goToTimelineHome} onOpenMovementLinks={openMovementLinks} />
         ) : (
           <div className="curator-login-gate">
             <h2>{t('curatorRequiredTitle')}</h2>
@@ -1145,6 +1165,25 @@ export default function HomePage() {
         )
       )}
 
+      {view.type === 'movement-links' && (
+        canInfluences ? (
+          <MovementLinksPage onBack={goToTimelineHome} movements={timelineData.movements} />
+        ) : (
+          <div className="curator-login-gate">
+            <h2>{t('curatorRequiredTitle')}</h2>
+            <p>{t('curatorRequiredBody')}</p>
+            <div className="curator-login-gate-actions">
+              <button type="button" className="checkup-link-btn" onClick={() => openCuratorLogin('movement-links')}>
+                {t('curatorLogin')}
+              </button>
+              <button type="button" className="debug-mode-toggle" onClick={goToTimelineHome}>
+                {t('backToGalleryBtn')}
+              </button>
+            </div>
+          </div>
+        )
+      )}
+
       {view.type === 'tours' && (
         canTours ? (
           <ToursPage onBack={goToTimelineHome} />
@@ -1273,6 +1312,14 @@ export default function HomePage() {
         <div className="home-page">
           <header className="site-header">
             <div className="site-layout-switch">
+              <button
+                type="button"
+                className="site-layout-link site-layout-link-feature"
+                onClick={openMovementLinks}
+                title="Manage art-movement predecessor → successor links (curator)"
+              >
+                {t('movementLinks')}
+              </button>
               {!isTreeTimeline && (
                 <button
                   type="button"

client/src/pages/InfluencesPage.tsx

@@ -16,6 +16,7 @@ type WizardStep = 'upload' | 'mapping' | 'preview' | 'done';
 
 interface Props {
   onBack: () => void;
+  onOpenMovementLinks?: () => void;
 }
 
 const ROLE_OPTIONS = [
@@ -29,7 +30,7 @@ const ROLE_OPTIONS = [
   'source_url',
 ] as const;
 
-export default function InfluencesPage({ onBack }: Props) {
+export default function InfluencesPage({ onBack, onOpenMovementLinks }: Props) {
   const { t } = useTranslation('influences');
   const [tab, setTab] = useState<Tab>('list');
   const [error, setError] = useState<string | null>(null);
@@ -335,6 +336,11 @@ export default function InfluencesPage({ onBack }: Props) {
           {t('back')}
         </button>
         <h1>{t('title')}</h1>
+        {onOpenMovementLinks && (
+          <button type="button" className="influences-back" onClick={onOpenMovementLinks}>
+            {t('openMovementLinks')}
+          </button>
+        )}
         <nav className="influences-tabs">
           <button type="button" className={tab === 'list' ? 'active' : ''} onClick={() => setTab('list')}>
             {t('tabList')}

client/src/pages/MovementLinksPage.css

@@ -0,0 +1,265 @@
+.movement-links-page {
+  max-width: 1100px;
+  margin: 0 auto;
+  padding: 1.25rem 1.5rem 3rem;
+  color: #e8d5b5;
+  min-height: 100vh;
+}
+
+.movement-links-header {
+  display: flex;
+  flex-wrap: wrap;
+  align-items: center;
+  gap: 0.75rem 1rem;
+  margin-bottom: 0.5rem;
+}
+
+.movement-links-header h1 {
+  margin: 0;
+  font-size: 1.5rem;
+  font-weight: 650;
+  flex: 1;
+  color: #e8d5b5;
+}
+
+.movement-links-back,
+.movement-links-add-btn,
+.movement-links-refresh,
+.movement-links-save,
+.movement-links-delete {
+  border: 1px solid rgba(201, 169, 110, 0.35);
+  background: rgba(15, 15, 26, 0.85);
+  color: #c9a96e;
+  border-radius: 6px;
+  padding: 0.4rem 0.75rem;
+  cursor: pointer;
+}
+
+.movement-links-back:hover,
+.movement-links-add-btn:hover,
+.movement-links-refresh:hover,
+.movement-links-save:hover {
+  border-color: #c9a96e;
+  color: #e8d5b5;
+}
+
+.movement-links-intro {
+  margin: 0 0 0.35rem;
+  color: rgba(232, 213, 181, 0.75);
+  font-size: 0.95rem;
+  max-width: 52rem;
+}
+
+.movement-links-intro-secondary {
+  margin: 0 0 1rem;
+  color: rgba(232, 213, 181, 0.55);
+  font-size: 0.88rem;
+  max-width: 52rem;
+}
+
+.movement-links-error {
+  background: rgba(139, 0, 0, 0.3);
+  border: 1px solid rgba(255, 170, 170, 0.4);
+  color: #ffaaaa;
+  padding: 0.65rem 0.85rem;
+  border-radius: 6px;
+  margin-bottom: 1rem;
+}
+
+.movement-links-form {
+  border: 1px solid rgba(201, 169, 110, 0.28);
+  border-radius: 8px;
+  padding: 1rem 1.1rem 1.15rem;
+  margin-bottom: 1.25rem;
+  background: rgba(15, 15, 26, 0.55);
+}
+
+.movement-links-form h2 {
+  margin: 0 0 0.85rem;
+  font-size: 1.1rem;
+  font-weight: 600;
+}
+
+.movement-links-form-grid {
+  display: grid;
+  grid-template-columns: 1fr 1fr;
+  gap: 0.75rem 1rem;
+  margin-bottom: 0.9rem;
+}
+
+.movement-links-form-grid label {
+  display: flex;
+  flex-direction: column;
+  gap: 0.35rem;
+  font-size: 0.85rem;
+  color: rgba(232, 213, 181, 0.85);
+}
+
+.movement-links-span-2 {
+  grid-column: 1 / -1;
+}
+
+.movement-links-form-grid select,
+.movement-links-form-grid input,
+.movement-links-form-grid textarea,
+.movement-links-vote-form textarea,
+.movement-links-search {
+  border: 1px solid rgba(201, 169, 110, 0.35);
+  background: rgba(10, 10, 20, 0.9);
+  color: #e8d5b5;
+  border-radius: 6px;
+  padding: 0.45rem 0.6rem;
+  font: inherit;
+}
+
+.movement-links-vote-form label {
+  display: flex;
+  flex-direction: column;
+  gap: 0.35rem;
+  margin-bottom: 0.75rem;
+  font-size: 0.85rem;
+  color: rgba(232, 213, 181, 0.85);
+}
+
+.movement-links-vote-actions {
+  display: flex;
+  flex-wrap: wrap;
+  gap: 0.5rem;
+}
+
+.movement-links-vote-btn,
+.movement-links-votes-toggle {
+  border: 1px solid rgba(201, 169, 110, 0.35);
+  background: rgba(15, 15, 26, 0.85);
+  color: #c9a96e;
+  border-radius: 6px;
+  padding: 0.35rem 0.65rem;
+  cursor: pointer;
+}
+
+.movement-links-vote-btn:hover,
+.movement-links-votes-toggle:hover {
+  border-color: #c9a96e;
+  color: #e8d5b5;
+}
+
+.movement-links-row-flagged {
+  background: rgba(232, 160, 64, 0.08);
+}
+
+.movement-links-vote-list {
+  margin: 0.45rem 0 0;
+  padding-left: 1.1rem;
+  color: rgba(232, 213, 181, 0.7);
+  font-size: 0.82rem;
+}
+
+.movement-links-actions {
+  white-space: nowrap;
+}
+
+.movement-links-save {
+  background: rgba(232, 160, 64, 0.18);
+  border-color: #e8a040;
+  color: #e8d5b5;
+}
+
+.movement-links-save:disabled,
+.movement-links-delete:disabled,
+.movement-links-refresh:disabled {
+  opacity: 0.55;
+  cursor: not-allowed;
+}
+
+.movement-links-toolbar {
+  display: flex;
+  flex-wrap: wrap;
+  align-items: center;
+  gap: 0.75rem;
+  margin-bottom: 0.75rem;
+}
+
+.movement-links-search {
+  flex: 1;
+  min-width: 12rem;
+}
+
+.movement-links-count {
+  color: rgba(232, 213, 181, 0.65);
+  font-size: 0.9rem;
+}
+
+.movement-links-muted {
+  color: rgba(232, 213, 181, 0.55);
+}
+
+.movement-links-table-wrap {
+  overflow-x: auto;
+  border: 1px solid rgba(201, 169, 110, 0.28);
+  border-radius: 8px;
+}
+
+.movement-links-table {
+  width: 100%;
+  border-collapse: collapse;
+  font-size: 0.92rem;
+}
+
+.movement-links-table th,
+.movement-links-table td {
+  text-align: left;
+  padding: 0.55rem 0.75rem;
+  border-bottom: 1px solid rgba(201, 169, 110, 0.18);
+  vertical-align: top;
+}
+
+.movement-links-table th {
+  background: rgba(15, 15, 26, 0.85);
+  color: #c9a96e;
+  font-weight: 600;
+  white-space: nowrap;
+}
+
+.movement-links-table tbody tr:nth-child(even) {
+  background: rgba(15, 15, 26, 0.35);
+}
+
+.movement-links-table a {
+  color: #e8a040;
+  word-break: break-word;
+}
+
+.movement-links-table a:hover {
+  color: #f0c070;
+}
+
+.movement-links-year {
+  white-space: nowrap;
+  font-variant-numeric: tabular-nums;
+}
+
+.movement-links-notes {
+  margin-top: 0.25rem;
+  color: rgba(232, 213, 181, 0.55);
+  font-size: 0.82rem;
+}
+
+.movement-links-delete {
+  color: #ffaaaa;
+  border-color: rgba(255, 170, 170, 0.35);
+}
+
+.movement-links-delete:hover:not(:disabled) {
+  border-color: #ffaaaa;
+  color: #ffcccc;
+}
+
+@media (max-width: 700px) {
+  .movement-links-form-grid {
+    grid-template-columns: 1fr;
+  }
+
+  .movement-links-span-2 {
+    grid-column: auto;
+  }
+}

client/src/pages/MovementLinksPage.tsx

@@ -0,0 +1,439 @@
+import { useCallback, useEffect, useMemo, useState } from 'react';
+import { useTranslation } from 'react-i18next';
+import {
+  api,
+  type MovementLineageDeleteVote,
+  type MovementLineageLinkItem,
+} from '../api/client';
+import { useAuth } from '../context/AuthContext';
+import { setMovementLineageFromApi } from '../data/movement-lineage';
+import type { ArtMovement } from '../types';
+import './MovementLinksPage.css';
+
+interface Props {
+  onBack: () => void;
+  movements: ArtMovement[];
+}
+
+export default function MovementLinksPage({ onBack, movements }: Props) {
+  const { t } = useTranslation('movementLinks');
+  const { isAdmin } = useAuth();
+  const [items, setItems] = useState<MovementLineageLinkItem[]>([]);
+  const [total, setTotal] = useState(0);
+  const [q, setQ] = useState('');
+  const [loading, setLoading] = useState(true);
+  const [saving, setSaving] = useState(false);
+  const [error, setError] = useState<string | null>(null);
+  const [showAdd, setShowAdd] = useState(false);
+
+  const [sourceId, setSourceId] = useState<number | ''>('');
+  const [targetId, setTargetId] = useState<number | ''>('');
+  const [proofUrl, setProofUrl] = useState('');
+  const [proofLabel, setProofLabel] = useState('');
+  const [linkYear, setLinkYear] = useState('');
+  const [notes, setNotes] = useState('');
+
+  const [voteLinkId, setVoteLinkId] = useState<number | null>(null);
+  const [voteReason, setVoteReason] = useState('');
+  const [expandedVotes, setExpandedVotes] = useState<Record<number, MovementLineageDeleteVote[] | 'loading' | 'error'>>({});
+
+  const sortedMovements = useMemo(
+    () => [...movements].sort((a, b) => a.start_year - b.start_year || a.name.localeCompare(b.name)),
+    [movements],
+  );
+
+  const syncLocalLineage = useCallback((rows: MovementLineageLinkItem[]) => {
+    setMovementLineageFromApi(rows);
+  }, []);
+
+  const loadList = useCallback(async () => {
+    setLoading(true);
+    setError(null);
+    try {
+      const [data, all] = await Promise.all([
+        api.listMovementLinks({ q: q || undefined, limit: 500 }),
+        q ? api.listMovementLinks({ limit: 500 }) : Promise.resolve(null),
+      ]);
+      setItems(data.items);
+      setTotal(data.total);
+      syncLocalLineage((all ?? data).items);
+    } catch (err) {
+      setError(err instanceof Error ? err.message : t('loadFailed'));
+    } finally {
+      setLoading(false);
+    }
+  }, [q, syncLocalLineage, t]);
+
+  useEffect(() => {
+    void loadList();
+  }, [loadList]);
+
+  const resetForm = () => {
+    setSourceId('');
+    setTargetId('');
+    setProofUrl('');
+    setProofLabel('');
+    setLinkYear('');
+    setNotes('');
+  };
+
+  const submitAdd = async () => {
+    if (sourceId === '' || targetId === '') {
+      setError(t('addRequiresMovements'));
+      return;
+    }
+    if (!proofUrl.trim()) {
+      setError(t('proofRequired'));
+      return;
+    }
+    setSaving(true);
+    setError(null);
+    try {
+      const yearRaw = linkYear.trim();
+      await api.createMovementLink({
+        sourceMovementId: sourceId,
+        targetMovementId: targetId,
+        proofUrl: proofUrl.trim(),
+        proofLabel: proofLabel.trim() || undefined,
+        linkYearApprox: yearRaw === '' ? null : Number(yearRaw),
+        notes: notes.trim() || undefined,
+      });
+      resetForm();
+      setShowAdd(false);
+      await loadList();
+    } catch (err) {
+      setError(err instanceof Error ? err.message : t('saveFailed'));
+    } finally {
+      setSaving(false);
+    }
+  };
+
+  const submitVote = async () => {
+    if (voteLinkId == null) return;
+    if (voteReason.trim().length < 10) {
+      setError(t('voteReasonRequired'));
+      return;
+    }
+    setSaving(true);
+    setError(null);
+    try {
+      await api.voteDeleteMovementLink(voteLinkId, voteReason.trim());
+      setVoteLinkId(null);
+      setVoteReason('');
+      setExpandedVotes((prev) => {
+        const next = { ...prev };
+        delete next[voteLinkId];
+        return next;
+      });
+      await loadList();
+    } catch (err) {
+      setError(err instanceof Error ? err.message : t('voteFailed'));
+    } finally {
+      setSaving(false);
+    }
+  };
+
+  const withdrawVote = async (id: number) => {
+    setSaving(true);
+    setError(null);
+    try {
+      await api.withdrawDeleteMovementLinkVote(id);
+      setExpandedVotes((prev) => {
+        const next = { ...prev };
+        delete next[id];
+        return next;
+      });
+      await loadList();
+    } catch (err) {
+      setError(err instanceof Error ? err.message : t('withdrawFailed'));
+    } finally {
+      setSaving(false);
+    }
+  };
+
+  const loadVotes = async (id: number) => {
+    if (expandedVotes[id] && expandedVotes[id] !== 'error') {
+      setExpandedVotes((prev) => {
+        const next = { ...prev };
+        delete next[id];
+        return next;
+      });
+      return;
+    }
+    setExpandedVotes((prev) => ({ ...prev, [id]: 'loading' }));
+    try {
+      const data = await api.listMovementLinkDeleteVotes(id);
+      setExpandedVotes((prev) => ({ ...prev, [id]: data.votes }));
+    } catch {
+      setExpandedVotes((prev) => ({ ...prev, [id]: 'error' }));
+    }
+  };
+
+  const onAdminDelete = async (id: number) => {
+    if (!window.confirm(t('confirmDelete'))) return;
+    setSaving(true);
+    setError(null);
+    try {
+      await api.deleteMovementLink(id);
+      setExpandedVotes((prev) => {
+        const next = { ...prev };
+        delete next[id];
+        return next;
+      });
+      await loadList();
+    } catch (err) {
+      setError(err instanceof Error ? err.message : t('deleteFailed'));
+    } finally {
+      setSaving(false);
+    }
+  };
+
+  return (
+    <div className="movement-links-page">
+      <header className="movement-links-header">
+        <button type="button" className="movement-links-back" onClick={onBack}>
+          {t('back')}
+        </button>
+        <h1>{t('title')}</h1>
+        <button
+          type="button"
+          className="movement-links-add-btn"
+          onClick={() => {
+            setShowAdd((v) => !v);
+            setError(null);
+          }}
+        >
+          {showAdd ? t('cancelAdd') : t('addLink')}
+        </button>
+        <button type="button" className="movement-links-refresh" onClick={() => void loadList()} disabled={loading}>
+          {t('refresh')}
+        </button>
+      </header>
+
+      <p className="movement-links-intro">{t('intro')}</p>
+      <p className="movement-links-intro-secondary">
+        {isAdmin ? t('introAdmin') : t('introCurator')}
+      </p>
+
+      {error && <div className="movement-links-error">{error}</div>}
+
+      {voteLinkId != null && (
+        <section className="movement-links-form movement-links-vote-form">
+          <h2>{t('voteTitle')}</h2>
+          <label className="movement-links-span-2">
+            {t('voteReason')} *
+            <textarea
+              rows={3}
+              value={voteReason}
+              onChange={(e) => setVoteReason(e.target.value)}
+              placeholder={t('voteReasonPlaceholder')}
+            />
+          </label>
+          <div className="movement-links-vote-actions">
+            <button type="button" className="movement-links-save" onClick={() => void submitVote()} disabled={saving}>
+              {saving ? t('saving') : t('submitVote')}
+            </button>
+            <button
+              type="button"
+              className="movement-links-refresh"
+              onClick={() => {
+                setVoteLinkId(null);
+                setVoteReason('');
+              }}
+              disabled={saving}
+            >
+              {t('cancelVote')}
+            </button>
+          </div>
+        </section>
+      )}
+
+      {showAdd && (
+        <section className="movement-links-form">
+          <h2>{t('addTitle')}</h2>
+          <div className="movement-links-form-grid">
+            <label>
+              {t('source')}
+              <select
+                value={sourceId === '' ? '' : String(sourceId)}
+                onChange={(e) => setSourceId(e.target.value ? Number(e.target.value) : '')}
+              >
+                <option value="">{t('pickMovement')}</option>
+                {sortedMovements.map((m) => (
+                  <option key={m.id} value={m.id}>
+                    {m.name} ({m.start_year})
+                  </option>
+                ))}
+              </select>
+            </label>
+            <label>
+              {t('target')}
+              <select
+                value={targetId === '' ? '' : String(targetId)}
+                onChange={(e) => setTargetId(e.target.value ? Number(e.target.value) : '')}
+              >
+                <option value="">{t('pickMovement')}</option>
+                {sortedMovements.map((m) => (
+                  <option key={m.id} value={m.id}>
+                    {m.name} ({m.start_year})
+                  </option>
+                ))}
+              </select>
+            </label>
+            <label className="movement-links-span-2">
+              {t('proofUrl')} *
+              <input
+                type="url"
+                required
+                placeholder="https://…"
+                value={proofUrl}
+                onChange={(e) => setProofUrl(e.target.value)}
+              />
+            </label>
+            <label>
+              {t('proofLabel')}
+              <input
+                type="text"
+                value={proofLabel}
+                onChange={(e) => setProofLabel(e.target.value)}
+                placeholder={t('proofLabelPlaceholder')}
+              />
+            </label>
+            <label>
+              {t('linkYear')}
+              <input
+                type="number"
+                value={linkYear}
+                onChange={(e) => setLinkYear(e.target.value)}
+                placeholder={t('linkYearPlaceholder')}
+              />
+            </label>
+            <label className="movement-links-span-2">
+              {t('notes')}
+              <input type="text" value={notes} onChange={(e) => setNotes(e.target.value)} />
+            </label>
+          </div>
+          <button type="button" className="movement-links-save" onClick={() => void submitAdd()} disabled={saving}>
+            {saving ? t('saving') : t('saveLink')}
+          </button>
+        </section>
+      )}
+
+      <div className="movement-links-toolbar">
+        <input
+          type="search"
+          className="movement-links-search"
+          placeholder={t('searchPlaceholder')}
+          value={q}
+          onChange={(e) => setQ(e.target.value)}
+        />
+        <span className="movement-links-count">{t('total', { count: total })}</span>
+      </div>
+
+      {loading ? (
+        <p className="movement-links-muted">{t('loading')}</p>
+      ) : items.length === 0 ? (
+        <p className="movement-links-muted">{t('noLinks')}</p>
+      ) : (
+        <div className="movement-links-table-wrap">
+          <table className="movement-links-table">
+            <thead>
+              <tr>
+                <th>{t('colSource')}</th>
+                <th>{t('colTarget')}</th>
+                <th>{t('colYear')}</th>
+                <th>{t('colProof')}</th>
+                <th>{t('colVotes')}</th>
+                <th>{t('colActions')}</th>
+              </tr>
+            </thead>
+            <tbody>
+              {items.map((row) => {
+                const voteCount = row.delete_vote_count ?? 0;
+                const votesState = expandedVotes[row.id];
+                return (
+                  <tr key={row.id} className={voteCount > 0 ? 'movement-links-row-flagged' : undefined}>
+                    <td>{row.source_name}</td>
+                    <td>{row.target_name}</td>
+                    <td className="movement-links-year">
+                      {row.link_year_approx != null ? `~${row.link_year_approx}` : '—'}
+                    </td>
+                    <td>
+                      <a href={row.proof_url} target="_blank" rel="noopener noreferrer">
+                        {row.proof_label || row.proof_url}
+                      </a>
+                      {row.notes ? <div className="movement-links-notes">{row.notes}</div> : null}
+                      {Array.isArray(votesState) && votesState.length > 0 && (
+                        <ul className="movement-links-vote-list">
+                          {votesState.map((v) => (
+                            <li key={v.id}>
+                              <strong>{v.username || `#${v.user_id}`}</strong>: {v.reason}
+                            </li>
+                          ))}
+                        </ul>
+                      )}
+                      {votesState === 'loading' && (
+                        <div className="movement-links-notes">{t('loadingVotes')}</div>
+                      )}
+                      {votesState === 'error' && (
+                        <div className="movement-links-notes">{t('votesLoadFailed')}</div>
+                      )}
+                    </td>
+                    <td className="movement-links-year">
+                      {voteCount > 0 ? (
+                        <button
+                          type="button"
+                          className="movement-links-votes-toggle"
+                          onClick={() => void loadVotes(row.id)}
+                        >
+                          {t('voteCount', { count: voteCount })}
+                        </button>
+                      ) : (
+                        '0'
+                      )}
+                    </td>
+                    <td className="movement-links-actions">
+                      {isAdmin ? (
+                        <button
+                          type="button"
+                          className="movement-links-delete"
+                          onClick={() => void onAdminDelete(row.id)}
+                          disabled={saving}
+                        >
+                          {t('delete')}
+                        </button>
+                      ) : row.viewer_has_delete_vote ? (
+                        <button
+                          type="button"
+                          className="movement-links-refresh"
+                          onClick={() => void withdrawVote(row.id)}
+                          disabled={saving}
+                        >
+                          {t('withdrawVote')}
+                        </button>
+                      ) : (
+                        <button
+                          type="button"
+                          className="movement-links-vote-btn"
+                          onClick={() => {
+                            setVoteLinkId(row.id);
+                            setVoteReason('');
+                            setError(null);
+                            setShowAdd(false);
+                          }}
+                          disabled={saving}
+                        >
+                          {t('voteDelete')}
+                        </button>
+                      )}
+                    </td>
+                  </tr>
+                );
+              })}
+            </tbody>
+          </table>
+        </div>
+      )}
+    </div>
+  );
+}

client/src/utils/movementTree.ts

@@ -34,7 +34,7 @@
  *    widest subtree first, so the main trunk keeps x = 0 (canvas centre).
  */
 import type { ArtMovement } from '../types';
-import { MOVEMENT_LINEAGE } from '../data/movement-lineage';
+import { getMovementLineage } from '../data/movement-lineage';
 
 /** All values are tree-space pixels; the renderer scales them to the canvas. */
 export const TREE_LAYOUT = {
@@ -103,7 +103,7 @@ function influenceCount(m: ArtMovement): number {
 function buildParentMap(movements: ArtMovement[]): Map<number, number[]> {
   const nameToId = new Map(movements.map((m) => [m.name, m.id]));
   const parents = new Map<number, number[]>();
-  for (const [parentName, childName] of MOVEMENT_LINEAGE) {
+  for (const [parentName, childName] of getMovementLineage()) {
     const parentId = nameToId.get(parentName);
     const childId = nameToId.get(childName);
     if (parentId == null || childId == null || parentId === childId) continue;

db/migrate-movement-link-delete-votes.sql

@@ -0,0 +1,16 @@
+-- Curator votes to delete a movement lineage link (admin performs the actual delete).
+
+CREATE TABLE IF NOT EXISTS movement_lineage_delete_votes (
+  id SERIAL PRIMARY KEY,
+  link_id INTEGER NOT NULL REFERENCES movement_lineage_links(id) ON DELETE CASCADE,
+  user_id INTEGER NOT NULL REFERENCES users(id) ON DELETE CASCADE,
+  reason TEXT NOT NULL,
+  created_at TIMESTAMPTZ NOT NULL DEFAULT now(),
+  CONSTRAINT movement_lineage_delete_votes_unique UNIQUE (link_id, user_id),
+  CONSTRAINT movement_lineage_delete_votes_reason_len CHECK (char_length(trim(reason)) >= 10)
+);
+
+CREATE INDEX IF NOT EXISTS movement_lineage_delete_votes_link_idx
+  ON movement_lineage_delete_votes (link_id);
+CREATE INDEX IF NOT EXISTS movement_lineage_delete_votes_user_idx
+  ON movement_lineage_delete_votes (user_id);

db/migrate-movement-links.sql

@@ -0,0 +1,37 @@
+-- Art-movement predecessor → successor edges for timeline / Tree of Art.
+-- Curators manage these with a required proof URL (literature or web essay).
+
+CREATE TABLE IF NOT EXISTS movement_lineage_links (
+  id SERIAL PRIMARY KEY,
+  source_movement_id INTEGER NOT NULL REFERENCES art_movements(id) ON DELETE CASCADE,
+  target_movement_id INTEGER NOT NULL REFERENCES art_movements(id) ON DELETE CASCADE,
+  link_year_approx INTEGER,
+  proof_url TEXT NOT NULL,
+  proof_label TEXT,
+  notes TEXT,
+  created_by INTEGER REFERENCES users(id) ON DELETE SET NULL,
+  created_at TIMESTAMPTZ NOT NULL DEFAULT now(),
+  updated_at TIMESTAMPTZ NOT NULL DEFAULT now(),
+  CONSTRAINT movement_lineage_links_distinct CHECK (source_movement_id <> target_movement_id),
+  CONSTRAINT movement_lineage_links_unique UNIQUE (source_movement_id, target_movement_id)
+);
+
+CREATE INDEX IF NOT EXISTS movement_lineage_links_source_idx
+  ON movement_lineage_links (source_movement_id);
+CREATE INDEX IF NOT EXISTS movement_lineage_links_target_idx
+  ON movement_lineage_links (target_movement_id);
+CREATE INDEX IF NOT EXISTS movement_lineage_links_year_idx
+  ON movement_lineage_links (link_year_approx);
+
+CREATE OR REPLACE FUNCTION movement_lineage_links_touch_updated_at()
+RETURNS TRIGGER AS $$
+BEGIN
+  NEW.updated_at = now();
+  RETURN NEW;
+END;
+$$ LANGUAGE plpgsql;
+
+DROP TRIGGER IF EXISTS movement_lineage_links_updated_at ON movement_lineage_links;
+CREATE TRIGGER movement_lineage_links_updated_at
+  BEFORE UPDATE ON movement_lineage_links
+  FOR EACH ROW EXECUTE PROCEDURE movement_lineage_links_touch_updated_at();

package.json

@@ -4,6 +4,7 @@
   "description": "",
   "main": "index.js",
   "scripts": {
+    "test": "node --test server/__tests__/**/*.test.js",
     "dev:web": "node scripts/dev-web.js",
     "dev:server": "nodemon server/index.js",
     "dev:client": "npm run dev --prefix client",

server/__tests__/movement-lineage-service.test.js

@@ -0,0 +1,129 @@
+/**
+ * Tests for movement lineage validation (run before / with the service module).
+ *   node --test server/__tests__/movement-lineage-service.test.js
+ */
+const { describe, it } = require('node:test');
+const assert = require('node:assert/strict');
+const {
+  isValidProofUrl,
+  validateCreatePayload,
+  validateDeleteVotePayload,
+  DEFAULT_MOVEMENT_LINEAGE,
+} = require('../movement-lineage-service');
+
+describe('isValidProofUrl', () => {
+  it('accepts http and https URLs', () => {
+    assert.equal(isValidProofUrl('https://www.metmuseum.org/toah/hd/byza/hd_byza.htm'), true);
+    assert.equal(isValidProofUrl('http://example.com/essay'), true);
+  });
+
+  it('rejects empty, non-http, and garbage', () => {
+    assert.equal(isValidProofUrl(''), false);
+    assert.equal(isValidProofUrl('   '), false);
+    assert.equal(isValidProofUrl(null), false);
+    assert.equal(isValidProofUrl('ftp://files.example/a'), false);
+    assert.equal(isValidProofUrl('not-a-url'), false);
+    assert.equal(isValidProofUrl('www.metmuseum.org/page'), false);
+  });
+});
+
+describe('validateCreatePayload', () => {
+  it('requires source, target, and proof URL', () => {
+    const r = validateCreatePayload({});
+    assert.equal(r.ok, false);
+    assert.match(r.error, /sourceMovementId/i);
+  });
+
+  it('rejects same source and target', () => {
+    const r = validateCreatePayload({
+      sourceMovementId: 3,
+      targetMovementId: 3,
+      proofUrl: 'https://www.theartstory.org/movement/cubism/',
+    });
+    assert.equal(r.ok, false);
+    assert.match(r.error, /different/i);
+  });
+
+  it('requires a valid proof URL', () => {
+    const r = validateCreatePayload({
+      sourceMovementId: 1,
+      targetMovementId: 2,
+      proofUrl: 'see Wikipedia',
+    });
+    assert.equal(r.ok, false);
+    assert.match(r.error, /proof/i);
+  });
+
+  it('accepts a valid payload and normalizes fields', () => {
+    const r = validateCreatePayload({
+      sourceMovementId: '10',
+      targetMovementId: 20,
+      proofUrl: '  https://www.metmuseum.org/essays/cubism  ',
+      proofLabel: '  Met Cubism  ',
+      linkYearApprox: '1907',
+      notes: ' Cézanne → Picasso ',
+    });
+    assert.equal(r.ok, true);
+    assert.deepEqual(r.value, {
+      sourceMovementId: 10,
+      targetMovementId: 20,
+      proofUrl: 'https://www.metmuseum.org/essays/cubism',
+      proofLabel: 'Met Cubism',
+      linkYearApprox: 1907,
+      notes: 'Cézanne → Picasso',
+    });
+  });
+
+  it('allows null optional year and blank optional label/notes', () => {
+    const r = validateCreatePayload({
+      sourceMovementId: 1,
+      targetMovementId: 2,
+      proofUrl: 'https://example.org/a',
+      proofLabel: '',
+      linkYearApprox: '',
+      notes: null,
+    });
+    assert.equal(r.ok, true);
+    assert.equal(r.value.proofLabel, null);
+    assert.equal(r.value.linkYearApprox, null);
+    assert.equal(r.value.notes, null);
+  });
+});
+
+describe('validateDeleteVotePayload', () => {
+  it('requires a non-empty reason', () => {
+    assert.equal(validateDeleteVotePayload({}).ok, false);
+    assert.equal(validateDeleteVotePayload({ reason: '  ' }).ok, false);
+    assert.match(validateDeleteVotePayload({ reason: '' }).error, /reason/i);
+  });
+
+  it('rejects reasons that are too short', () => {
+    const r = validateDeleteVotePayload({ reason: 'no' });
+    assert.equal(r.ok, false);
+    assert.match(r.error, /reason/i);
+  });
+
+  it('accepts and trims a valid reason', () => {
+    const r = validateDeleteVotePayload({
+      reason: '  Incorrect lineage: Cubism did not derive from Fauvism.  ',
+    });
+    assert.equal(r.ok, true);
+    assert.equal(r.value.reason, 'Incorrect lineage: Cubism did not derive from Fauvism.');
+  });
+});
+
+describe('DEFAULT_MOVEMENT_LINEAGE', () => {
+  it('has unique source→target pairs with proof URLs', () => {
+    assert.ok(DEFAULT_MOVEMENT_LINEAGE.length >= 20);
+    const keys = new Set();
+    for (const row of DEFAULT_MOVEMENT_LINEAGE) {
+      assert.ok(row.sourceName);
+      assert.ok(row.targetName);
+      assert.notEqual(row.sourceName, row.targetName);
+      assert.equal(isValidProofUrl(row.proofUrl), true, row.proofUrl);
+      const key = `${row.sourceName}→${row.targetName}`;
+      assert.equal(keys.has(key), false, `duplicate ${key}`);
+      keys.add(key);
+    }
+  });
+});

server/index.js

@@ -50,6 +50,7 @@ app.use('/api/users', usersRoutes);
 app.use('/api/audit', auditRoutes);
 app.use('/api/translations', translationRoutes);
 app.use('/api/influences', influenceRoutes);
+app.use('/api/movement-links', require('./routes/movement-links'));
 app.use('/api/tours', tourRoutes);
 app.use(
   '/images',

server/migrate.js

@@ -18,6 +18,8 @@ const INCREMENTAL_MIGRATIONS = [
   'migrate-tours.sql',
   'migrate-curator-notes.sql',
   'migrate-user-roles.sql',
+  'migrate-movement-links.sql',
+  'migrate-movement-link-delete-votes.sql',
 ];
 
 const BOOTSTRAP_ADMIN_PERMISSIONS = [
@@ -80,6 +82,15 @@ async function migrate() {
   console.log('Bootstrapping curator account (if needed) …');
   await bootstrapCurator();
 
+  try {
+    const { seedDefaultsIfEmpty } = require('./movement-lineage-service');
+    console.log('Seeding movement lineage defaults (if empty) …');
+    const seed = await seedDefaultsIfEmpty();
+    console.log(`  movement lineage: inserted=${seed.inserted}${seed.skipped ? ' (skipped)' : ''}`);
+  } catch (err) {
+    console.warn(`  movement lineage seed skipped: ${err.message}`);
+  }
+
   console.log('Database migration complete.');
 }
 

server/movement-lineage-service.js

@@ -0,0 +1,581 @@
+/**
+ * Movement predecessor → successor lineage (timeline branches / Tree of Art).
+ * Curators manage rows with required proof URLs; defaults seed from scholarship.
+ */
+
+const pool = require('./db');
+
+/** @typedef {{ sourceName: string, targetName: string, linkYearApprox: number | null, proofUrl: string, proofLabel: string }} DefaultLink */
+
+/** @type {ReadonlyArray<DefaultLink>} */
+const DEFAULT_MOVEMENT_LINEAGE = Object.freeze([
+  {
+    sourceName: 'Ancient Greek & Roman',
+    targetName: 'Byzantine',
+    linkYearApprox: 330,
+    proofUrl: 'https://www.metmuseum.org/toah/hd/byza/hd_byza.htm',
+    proofLabel: 'Met — Byzantine art',
+  },
+  {
+    sourceName: 'Byzantine',
+    targetName: 'Gothic',
+    linkYearApprox: 1150,
+    proofUrl: 'https://www.metmuseum.org/toah/hd/mgot/hd_mgot.htm',
+    proofLabel: 'Met — Gothic art',
+  },
+  {
+    sourceName: 'Gothic',
+    targetName: 'Early Renaissance',
+    linkYearApprox: 1400,
+    proofUrl: 'https://www.metmuseum.org/toah/hd/elar/hd_elar.htm',
+    proofLabel: 'Met — Florence & Early Renaissance',
+  },
+  {
+    sourceName: 'Northern Renaissance',
+    targetName: 'Early Renaissance',
+    linkYearApprox: 1420,
+    proofUrl: 'https://www.metmuseum.org/toah/hd/enet/hd_enet.htm',
+    proofLabel: 'Met — Early Netherlandish painting',
+  },
+  {
+    sourceName: 'Early Renaissance',
+    targetName: 'High Renaissance',
+    linkYearApprox: 1490,
+    proofUrl: 'https://www.metmuseum.org/toah/hd/hiren/hd_hiren.htm',
+    proofLabel: 'Met — High Renaissance',
+  },
+  {
+    sourceName: 'High Renaissance',
+    targetName: 'Mannerism',
+    linkYearApprox: 1520,
+    proofUrl: 'https://www.metmuseum.org/toah/hd/zino/hd_zino.htm',
+    proofLabel: 'Met — Mannerism',
+  },
+  {
+    sourceName: 'Mannerism',
+    targetName: 'Baroque',
+    linkYearApprox: 1600,
+    proofUrl: 'https://www.metmuseum.org/toah/hd/baro/hd_baro.htm',
+    proofLabel: 'Met — Baroque Rome',
+  },
+  {
+    sourceName: 'Baroque',
+    targetName: 'Rococo',
+    linkYearApprox: 1700,
+    proofUrl: 'https://www.metmuseum.org/toah/ht/09/euwf.html',
+    proofLabel: 'Met — France 1600–1800 (Rococo)',
+  },
+  {
+    sourceName: 'Rococo',
+    targetName: 'Neoclassicism',
+    linkYearApprox: 1760,
+    proofUrl: 'https://www.metmuseum.org/toah/ht/09/euwf.html',
+    proofLabel: 'Met — France 1600–1800 (Neoclassicism)',
+  },
+  {
+    sourceName: 'Neoclassicism',
+    targetName: 'Romanticism',
+    linkYearApprox: 1800,
+    proofUrl: 'https://www.metmuseum.org/toah/ht/10/euwf.html',
+    proofLabel: 'Met — France 1800–1900',
+  },
+  {
+    sourceName: 'Romanticism',
+    targetName: 'Realism',
+    linkYearApprox: 1840,
+    proofUrl: 'https://www.metmuseum.org/toah/hd/gust/hd_gust.htm',
+    proofLabel: 'Met — Gustave Courbet / Realism',
+  },
+  {
+    sourceName: 'Romanticism',
+    targetName: 'Impressionism',
+    linkYearApprox: 1860,
+    proofUrl: 'https://www.theartstory.org/movement/impressionism/',
+    proofLabel: 'TheArtStory — Impressionism',
+  },
+  {
+    sourceName: 'Realism',
+    targetName: 'Impressionism',
+    linkYearApprox: 1860,
+    proofUrl: 'https://www.metmuseum.org/toah/hd/imml/hd_imml.htm',
+    proofLabel: 'Met — Impressionism',
+  },
+  {
+    sourceName: 'Impressionism',
+    targetName: 'Post-Impressionism',
+    linkYearApprox: 1880,
+    proofUrl: 'https://www.theartstory.org/movement/post-impressionism/',
+    proofLabel: 'TheArtStory — Post-Impressionism',
+  },
+  {
+    sourceName: 'Post-Impressionism',
+    targetName: 'Symbolism',
+    linkYearApprox: 1880,
+    proofUrl: 'https://www.theartstory.org/movement/symbolism/',
+    proofLabel: 'TheArtStory — Symbolism',
+  },
+  {
+    sourceName: 'Post-Impressionism',
+    targetName: 'Fauvism',
+    linkYearApprox: 1904,
+    proofUrl: 'https://www.theartstory.org/movement/fauvism/',
+    proofLabel: 'TheArtStory — Fauvism',
+  },
+  {
+    sourceName: 'Post-Impressionism',
+    targetName: 'Expressionism',
+    linkYearApprox: 1905,
+    proofUrl: 'https://www.theartstory.org/movement/expressionism/',
+    proofLabel: 'TheArtStory — Expressionism',
+  },
+  {
+    sourceName: 'Post-Impressionism',
+    targetName: 'Cubism',
+    linkYearApprox: 1907,
+    proofUrl: 'https://www.metmuseum.org/essays/cubism',
+    proofLabel: 'Met — Cubism',
+  },
+  {
+    sourceName: 'Symbolism',
+    targetName: 'Art Nouveau',
+    linkYearApprox: 1890,
+    proofUrl: 'https://www.theartstory.org/movement/art-nouveau/',
+    proofLabel: 'TheArtStory — Art Nouveau',
+  },
+  {
+    sourceName: 'Fauvism',
+    targetName: 'Cubism',
+    linkYearApprox: 1907,
+    proofUrl:
+      'https://www.christies.com/en/stories/from-fauvism-to-cubism-bc026df2c6774575938a4e26cacb8259',
+    proofLabel: "Christie's — From Fauvism to Cubism",
+  },
+  {
+    sourceName: 'Cubism',
+    targetName: 'Futurism',
+    linkYearApprox: 1909,
+    proofUrl: 'https://www.theartstory.org/movement/futurism/',
+    proofLabel: 'TheArtStory — Futurism',
+  },
+  {
+    sourceName: 'Cubism',
+    targetName: 'Suprematism',
+    linkYearApprox: 1913,
+    proofUrl: 'https://www.theartstory.org/movement/suprematism/',
+    proofLabel: 'TheArtStory — Suprematism',
+  },
+  {
+    sourceName: 'Cubism',
+    targetName: 'Constructivism',
+    linkYearApprox: 1913,
+    proofUrl: 'https://www.theartstory.org/movement/constructivism/',
+    proofLabel: 'TheArtStory — Constructivism',
+  },
+  {
+    sourceName: 'Expressionism',
+    targetName: 'Abstract Expressionism',
+    linkYearApprox: 1940,
+    proofUrl: 'https://www.theartstory.org/movement/abstract-expressionism/',
+    proofLabel: 'TheArtStory — Abstract Expressionism',
+  },
+  {
+    sourceName: 'Dada',
+    targetName: 'Surrealism',
+    linkYearApprox: 1924,
+    proofUrl: 'https://www.theartstory.org/movement/dada/',
+    proofLabel: 'TheArtStory — Dada',
+  },
+  {
+    sourceName: 'Surrealism',
+    targetName: 'Abstract Expressionism',
+    linkYearApprox: 1940,
+    proofUrl: 'https://www.theartstory.org/artist/breton-andre/',
+    proofLabel: 'TheArtStory — André Breton',
+  },
+  {
+    sourceName: 'Abstract Expressionism',
+    targetName: 'Pop Art',
+    linkYearApprox: 1955,
+    proofUrl: 'https://www.theartstory.org/movement/pop-art/',
+    proofLabel: 'TheArtStory — Pop Art',
+  },
+]);
+
+function isValidProofUrl(value) {
+  if (typeof value !== 'string') return false;
+  const trimmed = value.trim();
+  if (!trimmed) return false;
+  try {
+    const u = new URL(trimmed);
+    return u.protocol === 'http:' || u.protocol === 'https:';
+  } catch {
+    return false;
+  }
+}
+
+function parsePositiveId(value) {
+  const n = Number(value);
+  return Number.isFinite(n) && n > 0 ? Math.floor(n) : null;
+}
+
+function parseOptionalYear(value) {
+  if (value == null || value === '') return null;
+  const n = Number(value);
+  if (!Number.isFinite(n)) return NaN;
+  return Math.trunc(n);
+}
+
+/**
+ * @param {unknown} body
+ * @returns {{ ok: true, value: object } | { ok: false, error: string }}
+ */
+function validateCreatePayload(body) {
+  const raw = body && typeof body === 'object' ? body : {};
+  const sourceMovementId = parsePositiveId(raw.sourceMovementId);
+  const targetMovementId = parsePositiveId(raw.targetMovementId);
+  if (!sourceMovementId) {
+    return { ok: false, error: 'sourceMovementId is required' };
+  }
+  if (!targetMovementId) {
+    return { ok: false, error: 'targetMovementId is required' };
+  }
+  if (sourceMovementId === targetMovementId) {
+    return { ok: false, error: 'source and target must be different movements' };
+  }
+  const proofUrlRaw = typeof raw.proofUrl === 'string' ? raw.proofUrl.trim() : '';
+  if (!isValidProofUrl(proofUrlRaw)) {
+    return { ok: false, error: 'proofUrl must be a valid http(s) URL (required)' };
+  }
+  const linkYearApprox = parseOptionalYear(raw.linkYearApprox);
+  if (Number.isNaN(linkYearApprox)) {
+    return { ok: false, error: 'linkYearApprox must be a number when provided' };
+  }
+  const proofLabel =
+    typeof raw.proofLabel === 'string' && raw.proofLabel.trim()
+      ? raw.proofLabel.trim()
+      : null;
+  const notes =
+    typeof raw.notes === 'string' && raw.notes.trim() ? raw.notes.trim() : null;
+
+  return {
+    ok: true,
+    value: {
+      sourceMovementId,
+      targetMovementId,
+      proofUrl: proofUrlRaw,
+      proofLabel,
+      linkYearApprox,
+      notes,
+    },
+  };
+}
+
+const MIN_DELETE_VOTE_REASON_LEN = 10;
+
+/**
+ * @param {unknown} body
+ * @returns {{ ok: true, value: { reason: string } } | { ok: false, error: string }}
+ */
+function validateDeleteVotePayload(body) {
+  const raw = body && typeof body === 'object' ? body : {};
+  const reason = typeof raw.reason === 'string' ? raw.reason.trim() : '';
+  if (!reason) {
+    return { ok: false, error: 'reason is required' };
+  }
+  if (reason.length < MIN_DELETE_VOTE_REASON_LEN) {
+    return {
+      ok: false,
+      error: `reason must be at least ${MIN_DELETE_VOTE_REASON_LEN} characters`,
+    };
+  }
+  return { ok: true, value: { reason } };
+}
+
+const LIST_SELECT = `
+  SELECT ml.id,
+         ml.source_movement_id,
+         ml.target_movement_id,
+         ml.link_year_approx,
+         ml.proof_url,
+         ml.proof_label,
+         ml.notes,
+         ml.created_at,
+         ml.updated_at,
+         s.name AS source_name,
+         s.start_year AS source_start_year,
+         t.name AS target_name,
+         t.start_year AS target_start_year,
+         (
+           SELECT COUNT(*)::int
+           FROM movement_lineage_delete_votes v
+           WHERE v.link_id = ml.id
+         ) AS delete_vote_count
+  FROM movement_lineage_links ml
+  JOIN art_movements s ON s.id = ml.source_movement_id
+  JOIN art_movements t ON t.id = ml.target_movement_id
+`;
+
+async function listLinks({ q, limit = 500, offset = 0, viewerUserId = null } = {}) {
+  const params = [];
+  const where = [];
+  if (q && typeof q === 'string' && q.trim()) {
+    params.push(`%${q.trim()}%`);
+    const i = params.length;
+    where.push(`(
+      s.name ILIKE $${i} OR t.name ILIKE $${i}
+      OR ml.proof_url ILIKE $${i} OR COALESCE(ml.proof_label, '') ILIKE $${i}
+      OR COALESCE(ml.notes, '') ILIKE $${i}
+    )`);
+  }
+  const whereSql = where.length ? `WHERE ${where.join(' AND ')}` : '';
+  params.push(Math.min(1000, Math.max(1, Number(limit) || 500)));
+  const limitIdx = params.length;
+  params.push(Math.max(0, Number(offset) || 0));
+  const offsetIdx = params.length;
+
+  const { rows } = await pool.query(
+    `${LIST_SELECT}
+     ${whereSql}
+     ORDER BY COALESCE(ml.link_year_approx, t.start_year) ASC NULLS LAST, s.name, t.name
+     LIMIT $${limitIdx} OFFSET $${offsetIdx}`,
+    params,
+  );
+
+  const countParams = params.slice(0, -2);
+  const { rows: countRows } = await pool.query(
+    `SELECT COUNT(*)::int AS n
+     FROM movement_lineage_links ml
+     JOIN art_movements s ON s.id = ml.source_movement_id
+     JOIN art_movements t ON t.id = ml.target_movement_id
+     ${whereSql}`,
+    countParams,
+  );
+
+  let items = rows;
+  if (viewerUserId && rows.length) {
+    const ids = rows.map((r) => r.id);
+    const { rows: myVotes } = await pool.query(
+      `SELECT link_id FROM movement_lineage_delete_votes
+       WHERE user_id = $1 AND link_id = ANY($2::int[])`,
+      [viewerUserId, ids],
+    );
+    const voted = new Set(myVotes.map((v) => v.link_id));
+    items = rows.map((r) => ({
+      ...r,
+      viewer_has_delete_vote: voted.has(r.id),
+    }));
+  } else {
+    items = rows.map((r) => ({ ...r, viewer_has_delete_vote: false }));
+  }
+
+  return { items, total: countRows[0]?.n ?? 0 };
+}
+
+async function createLink(payload, { userId } = {}) {
+  const validated = validateCreatePayload(payload);
+  if (!validated.ok) {
+    const err = new Error(validated.error);
+    err.status = 400;
+    throw err;
+  }
+  const v = validated.value;
+
+  const movements = await pool.query(
+    `SELECT id FROM art_movements WHERE id = ANY($1::int[])`,
+    [[v.sourceMovementId, v.targetMovementId]],
+  );
+  if (movements.rows.length !== 2) {
+    const err = new Error('source or target movement not found');
+    err.status = 400;
+    throw err;
+  }
+
+  try {
+    const { rows } = await pool.query(
+      `INSERT INTO movement_lineage_links
+         (source_movement_id, target_movement_id, link_year_approx, proof_url, proof_label, notes, created_by)
+       VALUES ($1, $2, $3, $4, $5, $6, $7)
+       RETURNING id`,
+      [
+        v.sourceMovementId,
+        v.targetMovementId,
+        v.linkYearApprox,
+        v.proofUrl,
+        v.proofLabel,
+        v.notes,
+        userId || null,
+      ],
+    );
+    const { rows: full } = await pool.query(`${LIST_SELECT} WHERE ml.id = $1`, [rows[0].id]);
+    return full[0];
+  } catch (e) {
+    if (e && e.code === '23505') {
+      const err = new Error('A link between these movements already exists');
+      err.status = 409;
+      throw err;
+    }
+    throw e;
+  }
+}
+
+async function deleteLink(id) {
+  const linkId = parsePositiveId(id);
+  if (!linkId) {
+    const err = new Error('Invalid link id');
+    err.status = 400;
+    throw err;
+  }
+  const { rows } = await pool.query(
+    `DELETE FROM movement_lineage_links WHERE id = $1 RETURNING id`,
+    [linkId],
+  );
+  if (!rows.length) {
+    const err = new Error('Link not found');
+    err.status = 404;
+    throw err;
+  }
+  return { id: linkId };
+}
+
+async function listDeleteVotes(linkId) {
+  const id = parsePositiveId(linkId);
+  if (!id) {
+    const err = new Error('Invalid link id');
+    err.status = 400;
+    throw err;
+  }
+  const { rows: linkRows } = await pool.query(
+    `SELECT id FROM movement_lineage_links WHERE id = $1`,
+    [id],
+  );
+  if (!linkRows.length) {
+    const err = new Error('Link not found');
+    err.status = 404;
+    throw err;
+  }
+  const { rows } = await pool.query(
+    `SELECT v.id, v.link_id, v.user_id, v.reason, v.created_at, u.username
+     FROM movement_lineage_delete_votes v
+     JOIN users u ON u.id = v.user_id
+     WHERE v.link_id = $1
+     ORDER BY v.created_at ASC`,
+    [id],
+  );
+  return { linkId: id, votes: rows };
+}
+
+async function castDeleteVote(linkId, body, { userId }) {
+  const id = parsePositiveId(linkId);
+  if (!id) {
+    const err = new Error('Invalid link id');
+    err.status = 400;
+    throw err;
+  }
+  if (!userId) {
+    const err = new Error('Curator login required');
+    err.status = 401;
+    throw err;
+  }
+  const validated = validateDeleteVotePayload(body);
+  if (!validated.ok) {
+    const err = new Error(validated.error);
+    err.status = 400;
+    throw err;
+  }
+
+  const { rows: linkRows } = await pool.query(
+    `SELECT id FROM movement_lineage_links WHERE id = $1`,
+    [id],
+  );
+  if (!linkRows.length) {
+    const err = new Error('Link not found');
+    err.status = 404;
+    throw err;
+  }
+
+  try {
+    const { rows } = await pool.query(
+      `INSERT INTO movement_lineage_delete_votes (link_id, user_id, reason)
+       VALUES ($1, $2, $3)
+       RETURNING id, link_id, user_id, reason, created_at`,
+      [id, userId, validated.value.reason],
+    );
+    return rows[0];
+  } catch (e) {
+    if (e && e.code === '23505') {
+      const err = new Error('You already voted to delete this link');
+      err.status = 409;
+      throw err;
+    }
+    throw e;
+  }
+}
+
+async function withdrawDeleteVote(linkId, { userId }) {
+  const id = parsePositiveId(linkId);
+  if (!id || !userId) {
+    const err = new Error('Invalid request');
+    err.status = 400;
+    throw err;
+  }
+  const { rows } = await pool.query(
+    `DELETE FROM movement_lineage_delete_votes
+     WHERE link_id = $1 AND user_id = $2
+     RETURNING id`,
+    [id, userId],
+  );
+  if (!rows.length) {
+    const err = new Error('Vote not found');
+    err.status = 404;
+    throw err;
+  }
+  return { id: rows[0].id, linkId: id };
+}
+
+/** Insert default scholarship links when the table is empty and movements exist. */
+async function seedDefaultsIfEmpty() {
+  const { rows: countRows } = await pool.query(
+    `SELECT COUNT(*)::int AS n FROM movement_lineage_links`,
+  );
+  if ((countRows[0]?.n ?? 0) > 0) return { inserted: 0, skipped: true };
+
+  const { rows: movements } = await pool.query(`SELECT id, name FROM art_movements`);
+  if (!movements.length) return { inserted: 0, skipped: true, reason: 'no movements' };
+
+  const byName = new Map(movements.map((m) => [m.name, m.id]));
+  let inserted = 0;
+  let missing = 0;
+  for (const row of DEFAULT_MOVEMENT_LINEAGE) {
+    const sourceId = byName.get(row.sourceName);
+    const targetId = byName.get(row.targetName);
+    if (!sourceId || !targetId) {
+      missing += 1;
+      continue;
+    }
+    const result = await pool.query(
+      `INSERT INTO movement_lineage_links
+         (source_movement_id, target_movement_id, link_year_approx, proof_url, proof_label)
+       VALUES ($1, $2, $3, $4, $5)
+       ON CONFLICT (source_movement_id, target_movement_id) DO NOTHING
+       RETURNING id`,
+      [sourceId, targetId, row.linkYearApprox, row.proofUrl, row.proofLabel],
+    );
+    if (result.rows.length) inserted += 1;
+  }
+  return { inserted, missing };
+}
+
+module.exports = {
+  DEFAULT_MOVEMENT_LINEAGE,
+  MIN_DELETE_VOTE_REASON_LEN,
+  isValidProofUrl,
+  validateCreatePayload,
+  validateDeleteVotePayload,
+  listLinks,
+  createLink,
+  deleteLink,
+  listDeleteVotes,
+  castDeleteVote,
+  withdrawDeleteVote,
+  seedDefaultsIfEmpty,
+};

server/routes/movement-links.js

@@ -0,0 +1,152 @@
+const express = require('express');
+const { requirePermission, requireAdmin } = require('../middleware/auth');
+const { logCuratorAction } = require('../audit-log');
+const {
+  listLinks,
+  createLink,
+  deleteLink,
+  listDeleteVotes,
+  castDeleteVote,
+  withdrawDeleteVote,
+  seedDefaultsIfEmpty,
+} = require('../movement-lineage-service');
+
+const router = express.Router();
+
+/** Optional staff session for vote annotations on list (public otherwise). */
+async function optionalStaff(req, _res, next) {
+  try {
+    if (req.session?.userId) {
+      const { loadStaffUser } = require('../middleware/auth');
+      const user = await loadStaffUser(req.session.userId);
+      if (user && user.is_active) {
+        req.curatorUser = user;
+      }
+    }
+  } catch {
+    /* ignore — list stays public */
+  }
+  next();
+}
+
+/** Public: timeline / tree consumers. */
+router.get('/', optionalStaff, async (req, res) => {
+  try {
+    await seedDefaultsIfEmpty();
+    const q = typeof req.query.q === 'string' ? req.query.q : '';
+    const limit = Number(req.query.limit) || 500;
+    const offset = Number(req.query.offset) || 0;
+    const data = await listLinks({
+      q,
+      limit,
+      offset,
+      viewerUserId: req.curatorUser?.id || null,
+    });
+    res.json(data);
+  } catch (err) {
+    console.error(err);
+    res.status(500).json({ error: 'Failed to list movement links' });
+  }
+});
+
+router.post('/', requirePermission('influences'), async (req, res) => {
+  try {
+    const item = await createLink(req.body || {}, { userId: req.session?.userId });
+    await logCuratorAction({
+      userId: req.session.userId,
+      action: 'movement_link.create',
+      resourceType: 'movement_lineage_link',
+      resourceId: item.id,
+      details: {
+        source_movement_id: item.source_movement_id,
+        target_movement_id: item.target_movement_id,
+        proof_url: item.proof_url,
+      },
+      req,
+    });
+    res.status(201).json({ item });
+  } catch (err) {
+    const status = err.status || 500;
+    if (status >= 500) console.error(err);
+    res.status(status).json({ error: err.message || 'Failed to create movement link' });
+  }
+});
+
+router.get('/:id/delete-votes', requirePermission('influences'), async (req, res) => {
+  try {
+    const data = await listDeleteVotes(req.params.id);
+    res.json(data);
+  } catch (err) {
+    const status = err.status || 500;
+    if (status >= 500) console.error(err);
+    res.status(status).json({ error: err.message || 'Failed to list delete votes' });
+  }
+});
+
+router.post('/:id/delete-votes', requirePermission('influences'), async (req, res) => {
+  try {
+    const vote = await castDeleteVote(req.params.id, req.body || {}, {
+      userId: req.session.userId,
+    });
+    await logCuratorAction({
+      userId: req.session.userId,
+      action: 'movement_link.delete_vote',
+      resourceType: 'movement_lineage_link',
+      resourceId: Number(req.params.id),
+      details: { reason: vote.reason },
+      req,
+    });
+    res.status(201).json({ vote });
+  } catch (err) {
+    const status = err.status || 500;
+    if (status >= 500) console.error(err);
+    res.status(status).json({ error: err.message || 'Failed to cast delete vote' });
+  }
+});
+
+router.delete('/:id/delete-votes/me', requirePermission('influences'), async (req, res) => {
+  try {
+    const result = await withdrawDeleteVote(req.params.id, { userId: req.session.userId });
+    await logCuratorAction({
+      userId: req.session.userId,
+      action: 'movement_link.delete_vote_withdraw',
+      resourceType: 'movement_lineage_link',
+      resourceId: result.linkId,
+      details: {},
+      req,
+    });
+    res.json({ ok: true, ...result });
+  } catch (err) {
+    const status = err.status || 500;
+    if (status >= 500) console.error(err);
+    res.status(status).json({ error: err.message || 'Failed to withdraw delete vote' });
+  }
+});
+
+/** Hard delete — admin only. Curators vote instead. */
+router.delete('/:id', requireAdmin, async (req, res) => {
+  try {
+    const votes = await listDeleteVotes(req.params.id).catch(() => ({ votes: [] }));
+    const result = await deleteLink(req.params.id);
+    await logCuratorAction({
+      userId: req.session.userId,
+      action: 'movement_link.delete',
+      resourceType: 'movement_lineage_link',
+      resourceId: result.id,
+      details: {
+        prior_votes: (votes.votes || []).map((v) => ({
+          username: v.username,
+          reason: v.reason,
+        })),
+      },
+      req,
+    });
+    res.json({ ok: true, id: result.id });
+  } catch (err) {
+    const status = err.status || 500;
+    if (status >= 500) console.error(err);
+    res.status(status).json({ error: err.message || 'Failed to delete movement link' });
+  }
+});
+
+module.exports = router;