test(v1): lock reconnect and disconnect-no-alarm behavior; close T-203

Adds a mid-stream drop recovery test and a pipeline test proving a
disconnected frame yields no events and interrupts a pending suspect
(stream loss never alarms). Live preview and fall detection on the real
Hikvision stream were confirmed on Windows. 74 tests pass.

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>

v1/tests/test_pipeline.py

@@ -121,6 +121,22 @@ def test_pipeline_from_config_uses_runtime_version_for_confirmed_event():
     assert result.events[0].config_version == config.runtime_config_version
 
 
+def test_disconnect_interrupts_suspect_without_alarm():
+    pipeline, machine = _pipeline([(_pose(),), (_pose(horizontal=True),)])
+
+    pipeline.process(_packet(0.0))
+    pipeline.process(_packet(0.1))
+    assert machine.state_of("P-0001") is FallState.SUSPECT
+
+    outage = pipeline.process(
+        FramePacket(image=None, timestamp_monotonic=1.0, status=SourceStatus.RETRYING)
+    )
+
+    assert outage.events == ()
+    assert outage.people == ()
+    assert machine.state_of("P-0001") is FallState.NORMAL
+
+
 def test_from_config_gives_each_run_a_unique_event_id():
     config = _config()