Give every movement its own period interior.

Movement halls routed 24 of the 26 movements through 8 generic detail kinds,
four of which (modern, industrial, atelier, museum) rendered nothing at all,
and `salon` was a single ceiling ring shared by eight movements.

`details` is now a 26-value MovementDetailKind, one per movement, each built
from the architecture of the same period as the movement itself. Gothic and
Byzantine are unchanged and stay in MovementHallDetails.tsx as the reference
implementations; the rest live under components/hall-details/, split by era,
over shared wall-flush primitives.

hall-details/geometry.ts records the budget the Gothic and Byzantine
components established, since frames hang 0.23 m proud with a 0.7 m clear
margin at each wall end: relief limits above and below the frame line, corner
pockets for freestanding masses, doorway and title-band clearance, and a cap
of two added lights per hall. Halls now pass their computed windows down so
upper-wall panels, arches and roundels step around the openings.

Also holds the pale interiors back from blowing out: gallery wall tints are
authored around 0.50-0.56 luminance instead of near-white, and the 19 halls
that read too bright take lightScale 0.30, matching the basilica.

Verified by rendering all 26 interiors offline at two hall sizes and
measuring the scene graph: nothing through walls, floor or ceiling, maximum
0.17 m intrusion into the hang zone, at most two added lights per hall.

Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>

Documentation/data-and-images.md

@@ -278,9 +278,38 @@ To add or fix a branch, edit `MOVEMENT_LINEAGE` in that file and rebuild the cli
 
 ## Movement gallery interiors (frontend)
 
-Separate from movement lineage layout, `client/src/data/movement-interior-styles.ts` defines a **unique 3D interior** for each seeded art movement (26 styles): wall/floor/ceiling textures, trim colours, window style, and architectural details (pilasters, coffered ceilings, etc.). Textures are generated procedurally in `client/src/utils/galleryProceduralTextures.ts` (colour maps in sRGB, normal maps in linear/`NoColorSpace`). Period mesh details live in `client/src/components/MovementHallDetails.tsx` — classical / neoclassical use **shallow engaged corner pilasters** so shafts never cover frames; Byzantine adds porphyry colonnettes / polycandela; Gothic (`details: 'gothic'`) adds bay-spaced compound piers with vault springers and transverse ribs flush to the side walls.
+Separate from movement lineage layout, `client/src/data/movement-interior-styles.ts` defines a **unique 3D interior** for each seeded art movement (26 styles): wall/floor/ceiling textures, trim colours, window style, and the `details` kind that selects its architecture. Textures are generated procedurally in `client/src/utils/galleryProceduralTextures.ts` (colour maps in sRGB, normal maps in linear/`NoColorSpace`).
 
-Gothic surfaces include **`gothic-ashlar`** (full-storey blind arcade mapped once vertically via `metersPerRepeat === WALL_HEIGHT`), **`gothic-vault`** (quadripartite rib bay), and **`gothic-stone-floor`**. Door-flanking wall panels use the hall wall texture via `GalleryWall` `kind`/`tint` so they match the textured walls. Deliberately dim naves set **`lightScale`** (Byzantine / Gothic) so shared lights stay soft while window shafts stay bright.
+### Period architecture per movement
+
+Every movement is built from the architecture of **its own period** — no two movements share an interior. `client/src/components/MovementHallDetails.tsx` dispatches on `style.details` (`MovementDetailKind`, 26 values) to one component:
+
+| Module | Movements |
+|--------|-----------|
+| `MovementHallDetails.tsx` (reference implementations) | `gothic` — bay-spaced compound piers, vault springers, transverse ribs · `byzantine` — porphyry colonnettes, basket capitals, revetment dado, hanging polycandela |
+| `hall-details/classical.tsx` | `roman` (Tuscan half-columns, dentil entablature, Pompeian socle) · `quattrocento` (pietra serena pilasters, blind arcade, tondi) · `cinquecento` (paired fluted Corinthian pilasters, Pantheon coffers) |
+| `hall-details/courtly.tsx` | `flemish` (linenfold wainscot, beam-and-corbel ceiling) · `mannerist` (herm pilasters, banded rustication, broken cornice) · `baroque` (solomonic corner columns, modillions, velvet field panels) · `rococo` (boiserie, rocaille cartouches, painted cove) · `neoclassical` (fluted Ionic order, meander frieze) |
+| `hall-details/nineteenth.tsx` | `gothic-revival` · `bourgeois` · `north-light` · `paris-atelier` · `symbolist` · `art-nouveau` |
+| `hall-details/modernism.tsx` | `fauvist` · `expressionist` · `cubist-atelier` · `futurist` · `suprematist` · `constructivist` · `dada` · `surrealist` · `loft` · `white-cube` |
+
+`hall-details/primitives.tsx` holds the wall-flush building blocks (`WallBand`, `CorniceRing`, `FlutedShaft`, capitals, `CofferedCeiling`, `HangingFixture`, `WallSconce`); `hall-details/geometry.ts` holds the shared hooks and the **geometry budget** every module has to obey, because frames hang 0.23 m proud of the wall face with a 0.7 m clear margin at each wall end:
+
+- relief below the frame line stays within **0.11 m** proud; friezes and cornices above 2.6 m within **0.17 m**
+- freestanding masses only inside the **0.34 m corner pocket**; nothing under 2.6 m within 1.45 m of a wall centre (doorways)
+- the end wall carries the hall title between **3.4 m and 3.9 m** — keep it clear
+- side-wall windows are placed at runtime between 2.4 m and 3.9 m, so panels, arches and roundels up there are filtered through **`useWallClearance`** (the hall passes its computed windows into `MovementHallDetails`)
+- at most **two added lights per hall**, so hall materials stay inside the WebGL light limits the shared track lighting already budgets for
+
+Gothic surfaces include **`gothic-ashlar`** (full-storey blind arcade mapped once vertically via `metersPerRepeat === WALL_HEIGHT`), **`gothic-vault`** (quadripartite rib bay), and **`gothic-stone-floor`**. Door-flanking wall panels use the hall wall texture via `GalleryWall` `kind`/`tint` so they match the textured walls.
+
+### Wall brightness
+
+Halls are lit by a shared rig with a high brightness floor, so a pale wall tint clips to flat white and loses its texture. Two settings control this together, and they **multiply**:
+
+- **tints** — gallery walls are authored around **0.50–0.56** relative luminance (0.66 for the Suprematist and Pop white cubes, 0.15–0.27 for the deliberately dark halls). Nothing sits near white.
+- **`lightScale`** — Gothic **0.26**, Byzantine **0.30**, and every formerly pale interior **0.30**; the already-dark halls keep **1**. Window fills are not scaled, so daylight shafts stay bright.
+
+When a hall reads too bright, prefer `lightScale`: it keeps the material colour believable (Byzantine's warm stone is a genuine `#a89880`, simply lit dimly) and avoids greying tints toward neutral. Remember that dimming a hall dims its paintings too — the lighting is shared, with no per-painting spots.
 
 Wing layout (up to 55 works per wing, U-shaped hang, window gap placement with packed-wall **clerestory** fallback) lives in `client/src/utils/movementHallLayout.ts`. Visit order fills the **left wall** (first work at the entrance), then the **far/end wall**, then the **right** (last work at the entrance). The same hang applies to artist halls and guided tours. Hall lighting is **shared** (no per-painting spotlights) so `MeshStandardMaterial` walls stay within WebGL light limits — see [basics.md](basics.md) § Shared 3D behaviour. To change a movement’s look, edit its entry in `movement-interior-styles.ts` and rebuild the client.