Add catalog search on timeline header and fix Back to Timeline navigation.

Public GET /api/search over artists, movements, and paintings with a debounced header bar on the timeline; Back to Timeline resets zoom and gallery session.

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

Documentation/API.md

@@ -171,6 +171,76 @@ Movements are filtered to those with at least one artist active in the requested
 
 ---
 
+## `GET /api/search`
+
+Public catalog search over **artists**, **paintings**, and **art movements**. Used by the timeline header search bar (`CatalogSearchBar.tsx`).
+
+**Query**
+
+| Param | Type | Default | Description |
+|-------|------|---------|-------------|
+| `q` | string | — | Search text (min **2** characters after trim; shorter returns `{ q, results: [] }`) |
+| `limit` | int | 20 | Max results total (capped at **50**) |
+| `types` | string | all | Optional comma list: `artist`, `painting`, `movement` |
+
+**Matching (case-insensitive `ILIKE`):**
+
+| Entity | Fields |
+|--------|--------|
+| Artist | `name`, `wikipedia_title`, movement name |
+| Movement | movement `name`, era name |
+| Painting | `title`, `wikipedia_title`, `year` (as text), artist name, movement name |
+
+Prefix matches on primary labels (`name` / `title`) rank before substring matches.
+
+**Response**
+
+```json
+{
+  "q": "monet",
+  "results": [
+    {
+      "type": "artist",
+      "id": 19,
+      "name": "Claude Monet",
+      "birth_year": 1840,
+      "death_year": 1926,
+      "movement_name": "Impressionism",
+      "portrait_path": "portraits/Claude_Monet.jpg",
+      "portrait_thumb_path": "portraits/thumbs/Claude_Monet_thumb.jpg"
+    },
+    {
+      "type": "movement",
+      "id": 12,
+      "name": "Impressionism",
+      "color": "#87CEEB",
+      "start_year": 1860,
+      "end_year": 1890,
+      "era_name": "Modern"
+    },
+    {
+      "type": "painting",
+      "id": 241,
+      "title": "Water Lilies",
+      "year": 1919,
+      "artist_id": 19,
+      "artist_name": "Claude Monet",
+      "movement_name": "Impressionism",
+      "thumbnail_path": "paintings/thumbs/Claude_Monet_Water_Lilies_thumb.jpg",
+      "image_path": "paintings/Claude_Monet_Water_Lilies.jpg"
+    }
+  ]
+}
+```
+
+**Indexes:** applied by `npm run dev:migrate` (`db/migrate-search.sql`) or standalone `npm run dev:migrate:search`.
+
+**Client:** `api.search(q, { limit?, types? })`.
+
+**Navigation from search:** choosing a **painting** opens detail with `returnTo: timeline`; the client shows **← Back to Timeline** and calls `goToTimelineHome()` (clears gallery session, resets timeline zoom). Choosing an **artist** or **movement** uses the normal gallery entry handlers.
+
+---
+
 ## `GET /api/artists`
 
 Artists for timeline portraits and the movement flow diagram.
@@ -720,6 +790,7 @@ The React client wraps these endpoints in `client/src/api/client.ts`. All reques
 | `logoutCurator()` | `POST /api/auth/logout` |
 | `api.getBounds()` | `GET /api/bounds` |
 | `api.getTimeline(start, end)` | `GET /api/timeline` |
+| `api.search(q, options?)` | `GET /api/search` |
 | `api.getArtists(...)` | `GET /api/artists` |
 | `api.getTimelineArtists()` | `GET /api/artists?timeline=1` |
 | `api.getArtist(id)` | `GET /api/artists/:id` |