[M2-TILE-02] Parallax tile layers + tile animation

[offdev]

M2-TILE-02 · Parallax tile layers + tile animation (FR-2.6)

Depends: M2-TILE-01, M2-PAR-01 (both merged). Scope only — nothing else.

Tile animation (data-driven frame cycling)

• TileAnimationDef — frameCount (1..kTileAnimMaxFrames = 64), frameTicks (the documented rate: simulation ticks per frame, ≥ 1), the tile sheet's SpriteFrameLayout (M2-SPRITE-03, texels).
• TileMap::Options::maxAnimations (1..kTileMapMaxAnimations = 256, default 8) — validated FIRST in create; the animation slot table is pre-sized at creation (id 0 = the static sentinel; 1..maxAnimations = animation slots). The tile's animationId is now consumed by the batch path (no longer inert data — existing tilemap goldens updated to static tiles).
• setAnimation(id, def) — setup/config path (the parallax setLayer precedent): first-failure-wins validation (id domain → frame count → tick rate → sheet extents → frameCount ≤ sheet frames → tight-sheet float-exact domain with the adversarial-layout u64 overflow guards), no log, rejected sets leave the slot unchanged; a success resets the phase and precomputes all frame UVs (the only per-animation allocation).
• advanceAnimations() — called once per sim tick (ARCH-002, never per render frame): every set animation's frame steps every frameTicks ticks, wrapping at frameCount (frame(ticks) = (ticks / frameTicks) mod frameCount). O(maxAnimations), zero allocation, no GL. Per-animation phase (all tiles of one animation in phase; per-tile offsets are the M3 editor's control). Frame state is presentation state (ARCH-009).
• Declared quads: the static tile carries DeclareOptions::uv + frameIndex 0; the animated tile carries its animation's current frame UV (precomputed) + frameIndex. An animated tile whose slot is unset fails the declare (first failure wins).
• setTile/rebuild gained the animationId ≤ maxAnimations check (whole span validated before any write).

Parallax tile layer (the M2-PAR-01 Tilemap-source hook, implemented)

• New TileMap::declareTo(batcher, options, layers, layerId, cameraPos) — every quad translated by the layer's worldOffset(cameraPos) (the M2-PAR-01 formula (1)); its key is the M2-ISO-01 key of the translated center at the tilemap's own Options::layer (scene-setup convention: the def's depthLayer must equal the tilemap's layer — bg/mid/fg tilemaps get −2/−1/+1). Translated keys computed per tile per frame (camera-dependent — O(tileCount), zero allocation; the qBase + qOffset derivation is the documented upgrade path).
• Protocol (first failure wins, nothing declared, no log): built frame / unset layer id / non-Tilemap-source layer → InvalidArgument; a disabled layer declares nothing (OK — the layer's documented skip).

Constraints honored

• No GL anywhere (pure data + batcher bookkeeping — compiles in every tree, no GPU execution).
• No per-frame allocation (FR-2.2): frame UVs precomputed at setAnimation, slot table at create — zero-alloc proof test: 1000 frames × (256 + 64 parallax tiles) of advance + declare + build under the owner-thread allocation window.
• No new budgets.json entry (count stays 16): the per-frame cost is part of the composite 50k render-CPU budget (M2-PERF-01).

Tests — new ctest entry tilemap_anim (12 tests / 6 suites, both backends, no GL)

• TileMapAnimSet — the setAnimation validation matrix (slot domain, frameCount [1,64] boundaries, tick rate, sheet domains, the adversarial tight-sheet overflow, rejected-set-leaves-no-state + phase reset) + no-log happy path.
• TileMapAnimCycle — the frame cycle at the documented rate, hand-computed frame = ticks / frameTicks mod frameCount over two independent animations.
• TileMapAnimDeclare — hand-computed frame-UV goldens (M2-SPRITE-03 tight-sheet formula), frameIndex, (atlas, material, blend) groups, the wrap, cross-frame bit-identical determinism.
• TileMapAnimParallax — golden-verified offsets at given camera positions (factor 0.25, center (4,4), offset (1,2); camera (10,6) → offset (2.5,2.5)) + hand-computed layer (−2) key goldens (0x7FA00060/0x7FA00070 — the 2^21 bias adds into bit 21) + the independent oracle (isoDepthKey on the translated centers, both backends) + layer-dominance ordering + the protocol paths + the animated tile under the translation.
• TileMapAnimProtocol — the animationId edit/load domain (out-of-range rejected, no state change) + the unset-slot declare failure.
• TileMapAnimZeroAlloc — the 1000-frame advance + declare zero-allocation loop (standalone + parallax).

Existing tilemap suites updated to the new static-sentinel semantics.

Verification

• All six local trees warning-clean: build 114/114, build-clang 114/114, build-release 103/103, build-shared 114/114, build-asan 111/111, build-tsan 111/111 (prior counts +1 each — the new tilemap_anim entry).
• ctest -R tilemap_anim green (12/12); ctest -R tilemap green (the unanchored regex also selects tilemap_anim — intended, documented in CMakeLists).
• laige-api.json regenerated last (1315 → 1342 symbols / 40 headers); api-real-tree/api-check-fresh, tools/laige-include-lint (69 files), tools/laige-determinism-lint (28 files, 0 violations) all green.
• Docs in the same patch: docs/api/tilemap.md (major), docs/api/parallax.md + parallax.h hook comments, docs/concepts/coordinates.md (§4.9/§4.10/§5), docs/README.md, src/laige-render/README.md.
• Roadmap box checked; progress board M2 19/33, total 65/194; change-log row.