feat: add ThreeJSWorldAdapter stub from Kimi's world analysis

Studied Kimi's AI World Builder (Kimisworld.zip, issue #870):
- React + Three.js app with runtime code generation via new Function()
- WorldObject schema: type, geometry, material, color, position, rotation,
  scale, animation string
- AI agent avatar with lerp-based movement, mood-based color, pulsing core
- State managed via Zustand; Bloom + ChromaticAberration post-processing

Adds ThreeJSWorldAdapter stub that maps Kimi's WorldObject schema to the
WorldInterface contract (observe/act/speak), documenting the HTTP/WS wiring
needed to bridge the Three.js app to Timmy's agent infrastructure.

The adapter's _object_to_entity_description() helper converts WorldObjects
into PerceptionOutput entity strings compatible with any WorldInterface
consumer, including the Morrowind integration.

Refs #870

src/infrastructure/world/adapters/threejs.py

@@ -0,0 +1,149 @@
+"""Three.js world adapter — bridges Kimi's AI World Builder to WorldInterface.
+
+Studied from Kimisworld.zip (issue #870).  Kimi's world is a React +
+Three.js app ("AI World Builder v1.0") that exposes a JSON state API and
+accepts ``addObject`` / ``updateObject`` / ``removeObject`` commands.
+
+This adapter is a stub: ``connect()`` and the core methods outline the
+HTTP / WebSocket wiring that would be needed to talk to a running instance.
+The ``observe()`` response maps Kimi's ``WorldObject`` schema to
+``PerceptionOutput`` entities so that any WorldInterface consumer can
+treat the Three.js canvas like any other game world.
+
+Usage::
+
+    registry.register("threejs", ThreeJSWorldAdapter)
+    adapter = registry.get("threejs", base_url="http://localhost:5173")
+    adapter.connect()
+    perception = adapter.observe()
+    adapter.act(CommandInput(action="add_object", parameters={"geometry": "sphere", ...}))
+    adapter.speak("Hello from Timmy", target="broadcast")
+"""
+
+from __future__ import annotations
+
+import logging
+
+from infrastructure.world.interface import WorldInterface
+from infrastructure.world.types import ActionResult, ActionStatus, CommandInput, PerceptionOutput
+
+logger = logging.getLogger(__name__)
+
+# ---------------------------------------------------------------------------
+# Kimi's WorldObject geometry / material vocabulary (from WorldObjects.tsx)
+# ---------------------------------------------------------------------------
+
+_VALID_GEOMETRIES = {"box", "sphere", "cylinder", "torus", "cone", "dodecahedron"}
+_VALID_MATERIALS = {"standard", "wireframe", "glass", "glow"}
+_VALID_TYPES = {"mesh", "light", "particle", "custom"}
+
+
+def _object_to_entity_description(obj: dict) -> str:
+    """Render a Kimi WorldObject dict as a human-readable entity string.
+
+    Example output: ``sphere/glow #ff006e at (2.1, 3.0, -1.5)``
+    """
+    geometry = obj.get("geometry", "unknown")
+    material = obj.get("material", "unknown")
+    color = obj.get("color", "#ffffff")
+    pos = obj.get("position", [0, 0, 0])
+    obj_type = obj.get("type", "mesh")
+    pos_str = "({:.1f}, {:.1f}, {:.1f})".format(*pos)
+    return f"{obj_type}/{geometry}/{material} {color} at {pos_str}"
+
+
+class ThreeJSWorldAdapter(WorldInterface):
+    """Adapter for Kimi's Three.js AI World Builder.
+
+    Connects to a running Three.js world that exposes:
+    - ``GET  /api/world/state``    — returns current WorldObject list
+    - ``POST /api/world/execute``  — accepts addObject / updateObject code
+    - WebSocket ``/ws/world``      — streams state change events
+
+    All core methods raise ``NotImplementedError`` until HTTP wiring is
+    added.  Implement ``connect()`` first — it should verify that the
+    Three.js app is running and optionally open a WebSocket for live events.
+
+    Key insight from studying Kimi's world (issue #870):
+    - Objects carry a geometry, material, color, position, rotation, scale,
+      and an optional *animation* string executed via ``new Function()``
+      each animation frame.
+    - The AI agent (``AIAgent.tsx``) moves through the world with lerp()
+      targeting, cycles through moods, and pulses its core during "thinking"
+      states — a model for how Timmy could manifest presence in a 3D world.
+    - World complexity is tracked as a simple counter (one unit per object)
+      which the AI uses to decide whether to create, modify, or upgrade.
+    """
+
+    def __init__(self, *, base_url: str = "http://localhost:5173") -> None:
+        self._base_url = base_url.rstrip("/")
+        self._connected = False
+
+    # -- lifecycle ---------------------------------------------------------
+
+    def connect(self) -> None:
+        raise NotImplementedError(
+            "ThreeJSWorldAdapter.connect() — verify Three.js app is running at "
+            f"{self._base_url} and optionally open a WebSocket to /ws/world"
+        )
+
+    def disconnect(self) -> None:
+        self._connected = False
+        logger.info("ThreeJSWorldAdapter disconnected")
+
+    @property
+    def is_connected(self) -> bool:
+        return self._connected
+
+    # -- core contract (stubs) ---------------------------------------------
+
+    def observe(self) -> PerceptionOutput:
+        """Return current Three.js world state as structured perception.
+
+        Expected HTTP call::
+
+            GET {base_url}/api/world/state
+            → {"objects": [...WorldObject], "worldComplexity": int, ...}
+
+        Each WorldObject becomes an entity description string.
+        """
+        raise NotImplementedError(
+            "ThreeJSWorldAdapter.observe() — GET /api/world/state, "
+            "map each WorldObject via _object_to_entity_description()"
+        )
+
+    def act(self, command: CommandInput) -> ActionResult:
+        """Dispatch a command to the Three.js world.
+
+        Supported actions (mirrors Kimi's CodeExecutor API):
+        - ``add_object``    — parameters: WorldObject fields (geometry, material, …)
+        - ``update_object`` — parameters: id + partial WorldObject fields
+        - ``remove_object`` — parameters: id
+        - ``clear_world``   — parameters: (none)
+
+        Expected HTTP call::
+
+            POST {base_url}/api/world/execute
+            Content-Type: application/json
+            {"action": "add_object", "parameters": {...}}
+        """
+        raise NotImplementedError(
+            f"ThreeJSWorldAdapter.act({command.action!r}) — "
+            "POST /api/world/execute with serialised CommandInput"
+        )
+
+    def speak(self, message: str, target: str | None = None) -> None:
+        """Inject a text message into the Three.js world.
+
+        Kimi's world does not have a native chat layer, so the recommended
+        implementation is to create a short-lived ``Text`` entity at a
+        visible position (or broadcast via the world WebSocket).
+
+        Expected WebSocket frame::
+
+            {"type": "timmy_speech", "text": message, "target": target}
+        """
+        raise NotImplementedError(
+            "ThreeJSWorldAdapter.speak() — send timmy_speech frame over "
+            "/ws/world WebSocket, or POST a temporary Text entity"
+        )