Phase 7: serve the vet sample from the template tools and docs

- build.py: _TEMPLATE_COMPONENTS rewritten around the vet sample (53 kinds —
  per-resource slices, jobs, worked appointment_reminder family, tests);
  seed tokens dropped from the manifest ('sample: vet' instead)
- registry.py: get_app_component(kind) no longer renames item/example seeds;
  prompts and tool docs updated to 'copy a slice and adapt'
- templates/README.md, 01_build_recipe, 40_ui_admin, wiki/03 updated off the
  old seed scheme; repo inventory/config now exclude vet (docs move under
  standards; react/vet itself is deleted in a later phase)
- regenerated MCP bundle, vendored templates, and site output

standards/mcp/templates/app/infra/adapters/actions_stream.py

@@ -0,0 +1,88 @@
+"""# Summary
+
+Species-scoped action stream — the SSE event source behind ``stream_actions``.
+
+---
+
+Every pet gets a background asyncio task that emits random, species-appropriate
+behaviors (a wagging dog, a kneading cat, a chirping bird) onto per-subscriber
+queues. The HTTP handler subscribes one queue per connected client and
+unsubscribes when the response closes.
+
+Notes:
+    Process-local and best-effort — the stream is generated, not persisted,
+    and is intentionally independent of the persistence backend.
+"""
+import asyncio
+import json
+import random
+
+_BEHAVIORS_BY_SPECIES: dict[str, list[str]] = {
+    "dog": ["wagging_tail", "stretching", "showing_belly", "barking", "panting"],
+    "cat": ["blep", "stretching", "showing_belly", "purring", "kneading"],
+    "bird": ["head_tilt", "stretching", "chirping", "wing_flap"],
+}
+
+_subscribers: dict[int, list[asyncio.Queue]] = {}
+_worker_tasks: dict[int, asyncio.Task] = {}
+
+
+async def _behavior_worker(pet_id: int, species: str) -> None:
+    """Emit random behaviors for one pet until cancelled.
+
+    Args:
+        pet_id (int): Pet whose subscribers receive the events.
+        species (str): Animal species selecting the behavior pool.
+    """
+    behaviors = _BEHAVIORS_BY_SPECIES.get(species, ["wagging_tail"])
+    while True:
+        action = random.choice(behaviors)
+        data = json.dumps({"action": action})
+        for q in _subscribers.get(pet_id, []):
+            await q.put(data)
+        await asyncio.sleep(random.uniform(1, 5))
+
+
+def _ensure_worker(pet_id: int, species: str) -> None:
+    """Start the behavior worker for ``pet_id`` if it is not running.
+
+    Args:
+        pet_id (int): Pet identifier.
+        species (str): Animal species selecting the behavior pool.
+    """
+    if pet_id not in _worker_tasks or _worker_tasks[pet_id].done():
+        _subscribers.setdefault(pet_id, [])
+        _worker_tasks[pet_id] = asyncio.create_task(_behavior_worker(pet_id, species))
+
+
+async def subscribe(pet_id: int, species: str) -> asyncio.Queue:
+    """Subscribe a new listener queue for a pet's action stream.
+
+    Args:
+        pet_id (int): Pet identifier.
+        species (str): Animal species selecting the behavior pool.
+
+    Returns:
+        asyncio.Queue: Queue that receives JSON-encoded action payloads.
+    """
+    q: asyncio.Queue = asyncio.Queue()
+    _subscribers.setdefault(pet_id, []).append(q)
+    _ensure_worker(pet_id, species)
+    return q
+
+
+def unsubscribe(pet_id: int, q: asyncio.Queue) -> None:
+    """Remove a listener queue and stop the worker when the last one leaves.
+
+    Args:
+        pet_id (int): Pet identifier.
+        q (asyncio.Queue): Queue returned by :func:`subscribe`.
+    """
+    queues = _subscribers.get(pet_id, [])
+    if q in queues:
+        queues.remove(q)
+    if not queues:
+        task = _worker_tasks.pop(pet_id, None)
+        if task and not task.done():
+            task.cancel()
+        _subscribers.pop(pet_id, None)