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>

tools/docgen/inventory.json

@@ -695,6 +695,9 @@
     "tiled-draw",
     "tiled-project",
     "tiled-tree",
-    "tiled-tile_prop"
+    "tiled-tile_prop",
+    "tiled-collide",
+    "tiled-collision_kind",
+    "tiled-tile_shapes"
   ]
 }