fix(webhooks): wire receiver to vector sync queue and fix registered URI

The /webhooks/nextcloud endpoint was a no-op stub that logged the
payload and returned 200 OK; webhook deletions never reached Qdrant.
Compounding that, _get_webhook_uri() registered the docker-compose
internal hostname (http://mcp:8000) with Nextcloud whenever
/.dockerenv existed — including ECS Fargate — so cloud deployments
were registering a URL NC could not resolve.

- New vector/webhook_parser.py extracts a DocumentTask from
  NodeCreatedEvent / NodeWrittenEvent / BeforeNodeDeletedEvent
  payloads scoped to */files/Notes/*.md (matching the registered
  preset filters).
- New vector/webhook_receiver.py pushes that task onto the same
  send-stream the scanner uses (app.state.document_send_stream),
  with 503 when sync is not running so NC retries delivery.
- _get_webhook_uri() now prefers NEXTCLOUD_MCP_SERVER_URL over the
  /.dockerenv branch, so the explicit public URL set on cloud tasks
  wins; docker-compose dev still falls back to the internal name when
  no public URL is configured.

Calendar / Tables event parsing is intentionally out of scope here.

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

tests/unit/test_webhook_endpoint.py

@@ -0,0 +1,144 @@
+"""Unit tests for the ``/webhooks/nextcloud`` HTTP receiver.
+
+Builds a minimal Starlette app around ``handle_nextcloud_webhook`` so we can
+drive it with ``TestClient`` without standing up the full FastMCP server.
+"""
+
+import anyio
+import pytest
+from starlette.applications import Starlette
+from starlette.routing import Route
+from starlette.testclient import TestClient
+
+from nextcloud_mcp_server.vector.webhook_receiver import handle_nextcloud_webhook
+
+pytestmark = pytest.mark.unit
+
+
+def _make_app(send_stream=None) -> Starlette:
+    app = Starlette(
+        routes=[
+            Route("/webhooks/nextcloud", handle_nextcloud_webhook, methods=["POST"])
+        ]
+    )
+    app.state.document_send_stream = send_stream
+    return app
+
+
+_NOTE_CREATED = {
+    "user": {"uid": "admin", "displayName": "admin"},
+    "time": 1762850245,
+    "event": {
+        "class": "OCP\\Files\\Events\\Node\\NodeCreatedEvent",
+        "node": {
+            "id": 437,
+            "path": "/admin/files/Notes/Webhooks/Webhook Test Note.md",
+        },
+    },
+}
+
+
+_NOTE_DELETED = {
+    "user": {"uid": "alice"},
+    "time": 1762851093,
+    "event": {
+        "class": "OCP\\Files\\Events\\Node\\BeforeNodeDeletedEvent",
+        "node": {"id": 99, "path": "/alice/files/Notes/foo.md"},
+    },
+}
+
+
+def test_index_event_queues_task_and_returns_200():
+    send_stream, receive_stream = anyio.create_memory_object_stream(max_buffer_size=4)
+    app = _make_app(send_stream=send_stream)
+
+    with TestClient(app) as client:
+        response = client.post("/webhooks/nextcloud", json=_NOTE_CREATED)
+
+    assert response.status_code == 200
+    assert response.json()["status"] == "queued"
+    assert response.json()["operation"] == "index"
+    assert response.json()["doc_id"] == "437"
+
+    task = receive_stream.receive_nowait()
+    assert task.user_id == "admin"
+    assert task.doc_id == "437"
+    assert task.operation == "index"
+    assert task.doc_type == "note"
+
+
+def test_delete_event_queues_delete_task():
+    send_stream, receive_stream = anyio.create_memory_object_stream(max_buffer_size=4)
+    app = _make_app(send_stream=send_stream)
+
+    with TestClient(app) as client:
+        response = client.post("/webhooks/nextcloud", json=_NOTE_DELETED)
+
+    assert response.status_code == 200
+    assert response.json()["operation"] == "delete"
+
+    task = receive_stream.receive_nowait()
+    assert task.operation == "delete"
+    assert task.doc_id == "99"
+    assert task.user_id == "alice"
+
+
+def test_unsupported_event_is_ignored():
+    send_stream, receive_stream = anyio.create_memory_object_stream(max_buffer_size=4)
+    app = _make_app(send_stream=send_stream)
+
+    payload = {
+        "user": {"uid": "admin"},
+        "time": 1,
+        "event": {
+            "class": "OCP\\Calendar\\Events\\CalendarObjectCreatedEvent",
+            "objectData": {"id": 7},
+        },
+    }
+
+    with TestClient(app) as client:
+        response = client.post("/webhooks/nextcloud", json=payload)
+
+    assert response.status_code == 200
+    assert response.json()["status"] == "ignored"
+
+    with pytest.raises(anyio.WouldBlock):
+        receive_stream.receive_nowait()
+
+
+def test_invalid_json_returns_400():
+    app = _make_app(send_stream=None)
+
+    with TestClient(app) as client:
+        response = client.post(
+            "/webhooks/nextcloud",
+            content=b"not json",
+            headers={"content-type": "application/json"},
+        )
+
+    assert response.status_code == 400
+    assert response.json()["status"] == "error"
+
+
+def test_returns_503_when_send_stream_not_wired():
+    """Vector sync not running → tell NC to retry instead of dropping the
+    event."""
+    app = _make_app(send_stream=None)
+
+    with TestClient(app) as client:
+        response = client.post("/webhooks/nextcloud", json=_NOTE_CREATED)
+
+    assert response.status_code == 503
+    assert response.json()["status"] == "unavailable"
+
+
+def test_returns_500_when_stream_is_closed():
+    send_stream, receive_stream = anyio.create_memory_object_stream(max_buffer_size=1)
+    receive_stream.close()  # close receiver → send raises BrokenResourceError
+    app = _make_app(send_stream=send_stream)
+
+    with TestClient(app) as client:
+        response = client.post("/webhooks/nextcloud", json=_NOTE_CREATED)
+
+    assert response.status_code == 500
+    assert response.json()["status"] == "error"