feat: embedded flow-watcher in API lifespan with startup sync

backend/app/main.py

@@ -1,8 +1,58 @@
+import asyncio
+import logging
+from collections.abc import AsyncIterator
+from contextlib import asynccontextmanager
+from pathlib import Path
+
 from fastapi import FastAPI
 
 from .flows.api import approvals_router, flows_router
+from .flows.sync import run_sync_blocking, watch_forever
 from .settings import settings
 
+logger = logging.getLogger(__name__)
+
+
+def _blocking_startup_sync() -> None:
+    """One-shot reconciliation at startup (fresh session, never fatal)."""
+    try:
+        report = run_sync_blocking(Path(settings.flows_dir))
+        logger.info(
+            "startup flow sync: +%d ~%d -%d skipped=%d errors=%d",
+            len(report.added),
+            len(report.updated),
+            len(report.deleted),
+            len(report.skipped),
+            len(report.errors),
+        )
+        for filename, reason in report.errors.items():
+            logger.warning("startup flow sync: %s: %s", filename, reason)
+    except FileNotFoundError as exc:
+        logger.error("startup flow sync skipped: %s", exc)
+    except Exception:  # noqa: BLE001 - API must start even if sync fails
+        logger.exception("startup flow sync failed")
+
+
+@asynccontextmanager
+async def lifespan(app: FastAPI) -> AsyncIterator[None]:
+    task: asyncio.Task | None = None
+    stop: asyncio.Event | None = None
+    if settings.flows_watch_enabled:
+        await asyncio.to_thread(_blocking_startup_sync)
+        stop = asyncio.Event()
+        task = asyncio.create_task(
+            watch_forever(stop, Path(settings.flows_dir)), name="flows-watcher"
+        )
+    yield
+    if task is not None and stop is not None:
+        stop.set()
+        task.cancel()
+        try:
+            await task
+        except (asyncio.CancelledError, Exception):  # noqa: BLE001 - shutdown
+            pass
+
+
 app = FastAPI(
     title="Kirche Einfach API",
     description="KI-gestützte Verwaltungsplattform für Kirche",
@@ -10,6 +60,7 @@ app = FastAPI(
     docs_url="/api/docs",
     redoc_url="/api/redoc",
     openapi_url="/api/openapi.json",
+    lifespan=lifespan,
 )
 
 app.include_router(flows_router)