fix: address PR #836 review — forward task_producer to MCP contexts + cleanups

🔴 nc_get_vector_sync_status reported pending=0 for INGEST_QUEUE=postgres: the
AppContext/OAuthAppContext per-session yields snapshotted the stream fields but
never forwarded task_producer, so lifespan_ctx.task_producer was always None.
Convert task_producer to a @property that reads _vector_sync_state live (like
eviction_task_group), removing the snapshot field so the yields can't drop it.
Add a regression test pinning the contract on both contexts.

🟡 Remove the unused _RECLAIM_TASK_NAME constant.
🟡 get_procrastinate_conninfo: warn + document that DATABASE_URL query params
   (application_name, connect_timeout, …) are dropped.
🟡 worker: open the procrastinate App once — apply_ingest_queue_schema gains
   manage_connection=False so the worker reuses its own open connector instead
   of a redundant open/close before run_worker_async.

🟢 Clarify the apply-schema broad-except comment (non-race errors re-raise) and
   document the deliberate Any typing in ingest_status.get_ingest_pending.

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>

nextcloud_mcp_server/app.py

@@ -355,10 +355,18 @@ class AppContext:
     storage: "RefreshTokenStorage | None" = None
     document_send_stream: MemoryObjectSendStream | None = None
     document_receive_stream: MemoryObjectReceiveStream | None = None
-    task_producer: "TaskProducer | None" = None
     shutdown_event: anyio.Event | None = None
     scanner_wake_event: anyio.Event | None = None
 
+    @property
+    def task_producer(self) -> "TaskProducer | None":
+        # Read dynamically from the module-level singleton (like
+        # eviction_task_group) rather than snapshotting at yield time — that way
+        # a session can't observe a stale ``None`` and the per-session yields
+        # can't forget to forward it (the bug this property replaces). The
+        # vector-sync status tool reads this for postgres-backend job counts.
+        return _vector_sync_state.task_producer
+
     @property
     def eviction_task_group(self) -> TaskGroup | None:
         # Read dynamically from the module-level singleton instead of
@@ -381,10 +389,14 @@ class OAuthAppContext:
     server_client_id: str | None = None  # MCP server's OAuth client ID (static or DCR)
     document_send_stream: MemoryObjectSendStream | None = None
     document_receive_stream: MemoryObjectReceiveStream | None = None
-    task_producer: "TaskProducer | None" = None
     shutdown_event: anyio.Event | None = None
     scanner_wake_event: anyio.Event | None = None
 
+    @property
+    def task_producer(self) -> "TaskProducer | None":
+        # See AppContext.task_producer for rationale.
+        return _vector_sync_state.task_producer
+
     @property
     def eviction_task_group(self) -> TaskGroup | None:
         # See AppContext.eviction_task_group for rationale.
@@ -606,8 +618,8 @@ async def app_lifespan_basic(server: FastMCP) -> AsyncIterator[AppContext]:
             document_receive_stream=_vector_sync_state.document_receive_stream,
             shutdown_event=_vector_sync_state.shutdown_event,
             scanner_wake_event=_vector_sync_state.scanner_wake_event,
-            # eviction_task_group is exposed via @property (reads
-            # _vector_sync_state at access time, not snapshot).
+            # task_producer and eviction_task_group are exposed via @property
+            # (read _vector_sync_state at access time, not snapshot).
         )
     finally:
         logger.info("Shutting down BasicAuth session")
@@ -1239,8 +1251,8 @@ def get_app(transport: str = "streamable-http", enabled_apps: list[str] | None =
                     document_receive_stream=_vector_sync_state.document_receive_stream,
                     shutdown_event=_vector_sync_state.shutdown_event,
                     scanner_wake_event=_vector_sync_state.scanner_wake_event,
-                    # eviction_task_group is exposed via @property (reads
-                    # _vector_sync_state at access time, not snapshot).
+                    # task_producer and eviction_task_group are exposed via
+                    # @property (read _vector_sync_state at access time).
                 )
             finally:
                 logger.info("Shutting down MCP server")