feat(stdlib): Tiled P2 — collision normalisation into the Solids feed (#70)

Normalise three collision sources into the byte tilemap esys_move / Grid.* /
Path.* read, in the design's priority order (§3.5):

- per-tile <objectgroup> hitboxes (Tiled.tile_shapes) — the precise source;
- the solid/oneway/trigger bool property convention (Tiled.collision_kind);
- the designated collision layer — any non-zero GID solid (Tiled.project),
  the fallback source, applied automatically on load.

Tiled.collide drives collision from a visual layer's per-tile metadata alone
(a tile with no collision metadata stays passable). tmap_collision_kind
classifies a GID (0 none / 1 solid / 2 one-way / 3 trigger) from its metadata;
the projection adds the collision-layer fallback.

Proven by library/tiled_p2.ludic (14 assertions): kind classification for each
source, the property convention and collision-layer fallback producing an
identical Solids feed, a per-tile-<objectgroup> floor blocking an esys_move
mover, and A* over a loaded map matching the hand-authored baseline. x test:
93 passed.

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

docs/language/tiled/tiled-collide.md

@@ -0,0 +1,14 @@
+---
+id: tiled-collide
+name: Tiled.collide
+category: tiled
+kind: namespace-method
+tokens: Tiled.collide
+sig: Tiled.collide(map, layer: int) -> void
+tip: Drive collision from per-tile metadata.
+order: 14
+ns: Tiled
+member: collide
+---
+
+Projects a layer to the byte tilemap driving collision from per-tile metadata alone — a tile's <code>&lt;objectgroup&gt;</code> hitbox or its <code>solid</code>/<code>oneway</code>/<code>trigger</code> property — so a tile with no collision metadata stays passable. Use this to drive collision from a visual layer; <a href="tiled-project"><code>Tiled.project</code></a> is the designated-collision-layer form where any non-zero GID is solid.

docs/language/tiled/tiled-collision_kind.md

@@ -0,0 +1,14 @@
+---
+id: tiled-collision_kind
+name: Tiled.collision_kind
+category: tiled
+kind: namespace-method
+tokens: Tiled.collision_kind
+sig: Tiled.collision_kind(map, gid: int) -> int
+tip: Classify a GID's collision from its tile metadata.
+order: 15
+ns: Tiled
+member: collision_kind
+---
+
+Returns the collision kind a GID resolves to from its tile metadata, in the design's priority order (per-tile <code>&lt;objectgroup&gt;</code> hitboxes, then the property convention): <code>0</code> none, <code>1</code> solid, <code>2</code> one-way, <code>3</code> trigger. The collision-layer fallback (any non-zero GID solid) is applied by <a href="tiled-project"><code>Tiled.project</code></a>, not here.

docs/language/tiled/tiled-tile_shapes.md

@@ -0,0 +1,14 @@
+---
+id: tiled-tile_shapes
+name: Tiled.tile_shapes
+category: tiled
+kind: namespace-method
+tokens: Tiled.tile_shapes
+sig: Tiled.tile_shapes(map, gid: int) -> int
+tip: Whether a GID's tile has a collision shape.
+order: 16
+ns: Tiled
+member: tile_shapes
+---
+
+Returns <code>1</code> if the tile a GID resolves to carries a per-tile <code>&lt;objectgroup&gt;</code> with at least one collision shape (rectangle/ellipse/polygon/point), else <code>0</code> — the precise collision source in the P2 priority order.