fix: well-form NOSONAR suppressions (SonarCloud S7632/S7503)

The new decomposition modules used `# NOSONAR: reason` (colon form), which
SonarCloud flags as a malformed suppression comment (python:S7632) and which
fails to suppress the intended issue. Switch to the repo's bare `# NOSONAR`
convention with the rationale in a comment above, matching config.py and
auth/storage.py. This also lets the suppression silence python:S7503 (async
method without await) on the protocol-required no-op aclose stubs.

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

nextcloud_mcp_server/vector/queue/nats.py

@@ -156,7 +156,10 @@ class NatsTaskProducer:
     ) -> None:
         return None
 
-    async def aclose(self) -> None:  # NOSONAR: async required by TaskProducer protocol
+    # The bare ``# NOSONAR`` silences ``python:S7503`` (async method without
+    # await): ``async def`` is required by the TaskProducer protocol, but this
+    # handle close is a genuine no-op.
+    async def aclose(self) -> None:  # NOSONAR
         # Per-handle close (e.g. a per-user scanner clone exiting). The bus
         # connection is shared and owned by the lifespan, so this is a no-op;
         # the connection is torn down once via ``drain()`` on shutdown.