feat(examples): Tiled+physics examples + ObjectLayer→collider bridge (B3)

[Exoridus]

What

Adds the v0.14 Phase 4 B3 deliverable: two runnable combined Tiled + physics examples plus a reusable ObjectLayer → collider bridge recipe, exercising the freshly-merged B1 (free body construction + world.add/world.attach, #156) and B2 (typed ObjectLayer schema, #157) APIs.

New examples (examples/physics/)

• sprite-follows-body — the minimal binding: world.attach(sprite, { … }) builds a body + collider and binds it; the sprite tracks the body each world.step, falling onto a static floor (Kenney platformer character).
• tiled-map-physics-actor — a hand-built TileMap rendered via TileMapNode (tilemap extension), an ObjectLayer of solid regions, the bridge turning that layer into static PhysicsBodys, and a dynamic actor that falls/bounces. The physics /debug overlay outlines every generated collider.

The bridge — examples/shared/physics-tilemap.ts

buildCollidersFromObjectLayer(world, layer, options) walks an ObjectLayer and adds one static body per closed-area object: Rectangle→BoxShape, Polygon→PolygonShape (convex; concave skipped with a warning), Ellipse→CircleShape (larger semi-axis). Point/polyline/tile are skipped. Forwards friction/restitution/filter and supports a custom accept predicate.

Placement rationale: the bridge lives in example/app land, not in either package. @codexo/exojs-tilemap must never depend on @codexo/exojs-physics and vice-versa (the B4/D4 ADR, #158, keeps geometry shared but collision detection separate). The recipe is the only place that legitimately depends on both, so app-land is the correct, coupling-free home — and it stays a copy-paste recipe rather than engine API.

Tests

test/site/physics-tilemap-bridge.test.ts (8 cases) drives the recipe end-to-end against the real (aliased-to-source) packages: rectangle/ellipse/polygon mapping + centring, skip rules, non-convex warn-and-skip, option forwarding, the accept predicate, and an integration test where a dynamic box comes to rest on a bridge-built floor.

Wiring

• tsconfig.examples.json: @codexo/exojs-physics + /debug path mappings.
• vitest.config.ts: @codexo/exojs-physics source alias (so the bridge test resolves).
• eslint.config.ts: example .js import-sort collapsed to a single group — the examples:sync transpile strips blank lines between import groups, so an example mixing a package import with a relative recipe import could otherwise never lint clean.
• examples/examples.json + site/src/lib/chapters.ts: new Physics category (catalog↔chapters parity is asserted in examples-catalog.test.ts).
• site/public/preview.html + site/scripts/sync-exo-vendor.ts: physics (+ /debug) and tilemap (+ /register) added to the playground import map and vendor sync so the examples actually run in the playground.

Verification (all green locally; CI builds no dist)

• pnpm typecheck:examples ✓
• pnpm lint (examples) + pnpm lint:packages ✓
• pnpm format:check ✓
• pnpm --filter @codexo/exojs-examples examples:sync (generated .js + catalog committed) ✓
• Bridge test ✓; full exojs project (2377) + exojs-physics/exojs-tilemap (352) ✓

Not merged.

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