fix: repair 10 stale tests in test_mqtt_handler.py and test_node_sweeper.py

All 10 failures were tests that had drifted behind the product code, not
regressions in it. Diagnosed each individually:

test_mqtt_handler.py:
- test_checkin_creates_new_node, test_checkin_new_node_defaults_lat_lon:
  unpacked 4 positional args from doc_set.call_args[0], but
  fstore.doc_set(collection, doc_id, data, merge=False) always passes
  merge as a kwarg, so only 3 positional args are ever recorded. Fixed
  the unpack to 3.
- test_call_start_creates_call_doc, test_call_start_uses_now_when_started_at_missing:
  mocked fstore.doc_get, but _on_call_start looks the node up via the
  cached fstore.doc_get_cached (added when Firestore reads were cut to
  stay in the free tier). The unmocked doc_get_cached returned a bare
  MagicMock, which isn't awaitable. Mocked doc_get_cached instead; also
  fixed the same 4-vs-3 positional-arg unpack on doc_set's merge=False call.
- test_call_end_updates_status_and_times, test_call_end_sets_audio_url_when_present:
  mocked fstore.doc_update, but _on_call_end now writes via
  fstore.doc_set(merge=True) (see the "Fix Upload 404 warning" commit —
  doc_update raised "No document to update" when call_end arrived before
  call_start). Also calls doc_get_cached to stamp org_id. Mocked
  doc_get_cached and asserted against doc_set instead of doc_update.

test_node_sweeper.py:
- test_stale_online_node_marked_offline, test_stale_recording_node_marked_offline,
  test_tz_naive_last_seen_is_handled, test_only_stale_nodes_updated_in_batch:
  _sweep() now calls app.routers.tokens.release_token(node_id) for every
  node it marks offline (added in 2a690ec, the PulseAudio/Discord-token
  work). These tests never mocked it, so the module-level
  patch("asyncio.to_thread", ...) meant for the node-query call leaked
  into release_token's own internal to_thread call, feeding it raw node
  dicts where it expected Firestore doc snapshots with .id — hence
  "AttributeError: 'dict' object has no attribute 'id'". Patched
  app.routers.tokens.release_token directly (it's imported inline inside
  _sweep, so patching the source module works); the batch test also now
  asserts release_token fires for exactly the two nodes that went offline.

No product code changed — app/internal/mqtt_handler.py, app/routers/tokens.py,
and app/internal/node_sweeper.py all behave as intended. This was pure test
drift across two unrelated feature additions (Firestore-read caching,
Discord-token release-on-offline) that landed without their tests being
updated.

93 passed, 0 failed.

Closes logan/server-26#10.

Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>

drb-c2-core/tests/test_node_sweeper.py

@@ -35,8 +35,16 @@ def _node_naive(node_id, status, age_seconds):
 async def test_stale_online_node_marked_offline():
     nodes = [_node("node-01", "online", age_seconds=120)]
 
+    # A stale node also triggers app.routers.tokens.release_token(node_id) —
+    # added by the PulseAudio/Discord-token work (commit 2a690ec). It's
+    # imported inline inside _sweep, so it must be patched at its source
+    # module rather than relying on the global asyncio.to_thread patch above,
+    # which is scoped to the node-query call and would otherwise feed
+    # release_token's own internal to_thread call the wrong shape of data
+    # (raw node dicts instead of Firestore doc snapshots with .id).
     with patch("asyncio.to_thread", new=AsyncMock(return_value=nodes)), \
-         patch("app.internal.node_sweeper.fstore") as mock_fstore:
+         patch("app.internal.node_sweeper.fstore") as mock_fstore, \
+         patch("app.routers.tokens.release_token", new=AsyncMock()):
         mock_fstore.doc_update = AsyncMock()
         await _sweep()
 
@@ -50,7 +58,8 @@ async def test_stale_recording_node_marked_offline():
     nodes = [_node("node-02", "recording", age_seconds=200)]
 
     with patch("asyncio.to_thread", new=AsyncMock(return_value=nodes)), \
-         patch("app.internal.node_sweeper.fstore") as mock_fstore:
+         patch("app.internal.node_sweeper.fstore") as mock_fstore, \
+         patch("app.routers.tokens.release_token", new=AsyncMock()):
         mock_fstore.doc_update = AsyncMock()
         await _sweep()
 
@@ -106,7 +115,8 @@ async def test_tz_naive_last_seen_is_handled():
     nodes = [_node_naive("node-06", "online", age_seconds=120)]
 
     with patch("asyncio.to_thread", new=AsyncMock(return_value=nodes)), \
-         patch("app.internal.node_sweeper.fstore") as mock_fstore:
+         patch("app.internal.node_sweeper.fstore") as mock_fstore, \
+         patch("app.routers.tokens.release_token", new=AsyncMock()):
         mock_fstore.doc_update = AsyncMock()
         await _sweep()
 
@@ -141,10 +151,16 @@ async def test_only_stale_nodes_updated_in_batch():
     ]
 
     with patch("asyncio.to_thread", new=AsyncMock(return_value=nodes)), \
-         patch("app.internal.node_sweeper.fstore") as mock_fstore:
+         patch("app.internal.node_sweeper.fstore") as mock_fstore, \
+         patch("app.routers.tokens.release_token", new=AsyncMock()) as mock_release:
         mock_fstore.doc_update = AsyncMock()
         await _sweep()
 
     assert mock_fstore.doc_update.call_count == 2
     updated_ids = {call.args[1] for call in mock_fstore.doc_update.call_args_list}
     assert updated_ids == {"node-08", "node-11"}
+
+    # Both newly-offline nodes should have their Discord token freed.
+    assert mock_release.call_count == 2
+    released_ids = {call.args[0] for call in mock_release.call_args_list}
+    assert released_ids == {"node-08", "node-11"}