feat: extension lifecycle hooks (__init__.py)

- restaurant_start spawns three permanent tasks:
    1. invoice listener (LNBits payment settlement)
    2. NostrClient bootstrap (after 10s grace for nostrclient ext)
    3. Nostr sync loop (after 15s)
- restaurant_stop cancels tasks and closes the WS.
- Module-level nostr_client = None when nostrclient unavailable;
  publishing helpers no-op gracefully in that case.

__init__.py

@@ -0,0 +1,89 @@
+import asyncio
+
+from fastapi import APIRouter
+from loguru import logger
+
+from .crud import db
+from .tasks import wait_for_paid_invoices
+from .views import restaurant_generic_router
+from .views_api import restaurant_api_router
+
+restaurant_ext: APIRouter = APIRouter(prefix="/restaurant", tags=["Restaurant"])
+restaurant_ext.include_router(restaurant_generic_router)
+restaurant_ext.include_router(restaurant_api_router)
+
+restaurant_static_files = [
+    {
+        "path": "/restaurant/static",
+        "name": "restaurant_static",
+    }
+]
+
+scheduled_tasks: list[asyncio.Task] = []
+
+# Module-level NostrClient — None when nostrclient extension is unavailable.
+# Populated by the lifecycle task below.
+nostr_client = None
+
+
+def restaurant_stop():
+    for task in scheduled_tasks:
+        try:
+            task.cancel()
+        except Exception as ex:
+            logger.warning(ex)
+
+    global nostr_client
+    if nostr_client:
+        asyncio.get_event_loop().create_task(nostr_client.stop())
+
+
+def restaurant_start():
+    from lnbits.tasks import create_permanent_unique_task
+
+    # Invoice listener — settles orders on payment, kicks off print jobs.
+    task1 = create_permanent_unique_task("ext_restaurant", wait_for_paid_invoices)
+    scheduled_tasks.append(task1)
+
+    async def _start_nostr_client():
+        global nostr_client
+        await asyncio.sleep(10)  # Wait for nostrclient to be ready
+        try:
+            from .nostr.nostr_client import NostrClient
+
+            nostr_client = NostrClient()
+            logger.info("[RESTAURANT] Starting NostrClient for menu + order sync")
+            await nostr_client.run_forever()
+        except Exception as e:
+            logger.warning(f"[RESTAURANT] NostrClient failed to start: {e}")
+            logger.info("[RESTAURANT] Restaurant will work without Nostr layer")
+
+    task2 = create_permanent_unique_task("ext_restaurant_nostr", _start_nostr_client)
+    scheduled_tasks.append(task2)
+
+    async def _sync_nostr_events():
+        global nostr_client
+        await asyncio.sleep(15)
+        if not nostr_client:
+            logger.info("[RESTAURANT] No NostrClient, skipping Nostr sync")
+            return
+        try:
+            from .nostr_sync import wait_for_nostr_events
+
+            await wait_for_nostr_events(nostr_client)
+        except Exception as e:
+            logger.error(f"[RESTAURANT] Nostr sync task failed: {e}")
+
+    task3 = create_permanent_unique_task(
+        "ext_restaurant_nostr_sync", _sync_nostr_events
+    )
+    scheduled_tasks.append(task3)
+
+
+__all__ = [
+    "db",
+    "restaurant_ext",
+    "restaurant_start",
+    "restaurant_static_files",
+    "restaurant_stop",
+]