feat(engine): Tiled P3 — animated tiles (deterministic frame clock) + tile objects (#71)

- Animated tiles: a tileset <animation>'s {tileid, duration} frames advance as a
  pure function of the fixed 60/s engine frame counter (the same clock SpriteAnim
  rides), so an animated GID resolves at draw to the current frame's GID with its
  flip flags preserved — deterministic, frame-identical across runs, ticks for
  free. Tiled.frame_gid(map, gid, frame) / Tiled.animated(map, gid) expose it;
  Tiled.draw_anim(map, camx, camy, frame) draws a map with animations advanced.
- Tile objects: object-layer entries with a `gid` draw the tile image (with their
  own flip flags), bottom-anchored at the object position, as placeable sprites;
  tmap_draw_full now renders object layers alongside tile layers.

Proven by library/tiled_p3.ludic (14 assertions): frame advance at authored
durations + wrap, flip flags riding an animation swap, tile-object parse + draw +
flip mirroring, and the design's named rpg/beach_tileset.tsx (33 <animation>
blocks / 131 frames). x test: 94 passed.

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>

changes/tiled-maps.md

@@ -7,3 +7,4 @@ type: feat
 - **P0.5 TMX/TSX reader (#68)** — `Tiled.read` / `Tiled.read_tsx` map the native XML formats onto the *same* intermediate the JSON path produces — a `Value` tree in Tiled's JSON schema, with every tile layer's data decoded to a dense GID list (CSV, base64, base64+zlib, base64+gzip). A CSV `.tmx` and a base64+zlib `.tmj` of the same map read structurally identically; the in-repo Kenney `sampleMap.tmx` + external `sampleSheet.tsx` load with no manual JSON re-export.
 - **P1 core load + render (#69)** — the runtime `rt_tmap` model (heap-allocated to `w·h`, lifting the old `96×64` cap), the GID resolver (`Tiled.resolve` → tileset / local id / H·V·D flips), image-backed rendering (`Tiled.draw`, flips applied at blit), and the legacy-tilemap compatibility projection so `Grid.*`/`Path.*`/`esys_move` keep working. `Tiled.load` reads either format, resolves external tilesets + images, and auto-projects a `collision` layer. The Kenney sample loads and renders pixel-identically from `.tmx` and `.tmj`; the `grid` and `physics_tiles` demos now run off a loaded map.
 - **P2 collision & grid (#70)** — normalise three collision sources into the byte tilemap `esys_move`/`Grid.*`/`Path.*` read, in the design's priority order: per-tile `<objectgroup>` hitboxes, the `solid`/`oneway`/`trigger` property convention (`Tiled.collision_kind`/`Tiled.tile_shapes`), and the designated collision layer (`Tiled.project`, any non-zero GID solid) — or drive collision from a visual layer's per-tile metadata alone (`Tiled.collide`). The property convention and the collision-layer fallback produce the same feed; `Path.a_star` over a loaded map matches the hand-authored baseline.
+- **P3 animated tiles + tile objects (#71)** — a tileset `<animation>` advances deterministically as a pure function of the fixed 60/s engine frame clock (`Tiled.frame_gid`/`Tiled.animated`), so an animated GID resolves at draw to the current frame's GID with its flip flags preserved and reproduces frame-for-frame across runs; `Tiled.draw_anim` draws a map with animations advanced. Object-layer entries with a `gid` render the tile image (with their own flips), bottom-anchored, as placeable sprites.