wip(k1): checkpoint connection recovery rewrite

Capture the current unreleased K1 connection, recovery, lifecycle, viewer, and test work as a single known-bad baseline for subsequent fixes.

tests/test_live_perception.py

@@ -97,6 +97,8 @@ def test_live_ingress_wire_is_self_delimiting_and_explicitly_non_authoritative()
     header_bytes = struct.unpack("!I", encoded[:4])[0]
     header = json.loads(encoded[4 : 4 + header_bytes])
     assert header["schema_version"] == LIVE_INGRESS_WIRE_SCHEMA
+    assert header["session_id"] == "session-1"
+    assert header["session_generation"] == 1
     assert header["payload_bytes"] == 4
     assert header["commands_enabled"] is False
     assert header["navigation_or_safety_accepted"] is False
@@ -157,14 +159,45 @@ def test_live_ingress_new_session_discards_queued_events_from_previous_session()
         events.append(event)
     assert len(events) == 1
     assert events[0].session_id == "session-2"
+    assert events[0].session_generation == 2
     assert events[0].modality == "control"
     assert events[0].payload == b'{"event":"session-start"}'
 
 
+def test_live_result_admission_is_bound_to_exact_session_generation() -> None:
+    ingress = LivePerceptionIngress()
+    ingress.begin_session("session-1")
+    first_generation = ingress.snapshot()["session_generation"]
+    ingress.end_session("session-1")
+    ingress.begin_session("session-2")
+    second_generation = ingress.snapshot()["session_generation"]
+    received: list[str] = []
+
+    assert (
+        ingress.admit_result(
+            session_id="session-1",
+            session_generation=first_generation,
+            receiver=lambda: not received.append("stale"),
+        )
+        is False
+    )
+    assert (
+        ingress.admit_result(
+            session_id="session-2",
+            session_generation=second_generation,
+            receiver=lambda: not received.append("current"),
+        )
+        is True
+    )
+    assert received == ["current"]
+
+
 def test_live_result_round_trip_keeps_video_mask_boxes_and_shadow_authority() -> None:
     mask = np.zeros((600, 800), dtype=np.uint8)
     mask[100:120, 200:240] = 4
     encoded = encode_live_perception_result(
+        session_id="session-1",
+        session_generation=1,
         frame_index=12,
         source_frame_index=44,
         session_seconds=1.25,
@@ -188,6 +221,8 @@ def test_live_result_round_trip_keeps_video_mask_boxes_and_shadow_authority() ->
     frame = decode_live_perception_result(encoded)
 
     assert frame.frame_index == 12
+    assert frame.session_id == "session-1"
+    assert frame.session_generation == 1
     assert frame.source_frame_index == 44
     assert frame.image_jpeg == b"\xff\xd8test\xff\xd9"
     assert frame.segmentation_mask is not None
@@ -200,6 +235,8 @@ def test_live_result_round_trip_keeps_video_mask_boxes_and_shadow_authority() ->
 def test_live_result_rejects_tampering_and_partial_cuboid() -> None:
     with pytest.raises(ValueError, match="cuboid is incomplete"):
         encode_live_perception_result(
+            session_id="session-1",
+            session_generation=1,
             frame_index=0,
             source_frame_index=0,
             session_seconds=0.0,
@@ -218,6 +255,8 @@ def test_live_result_rejects_tampering_and_partial_cuboid() -> None:
             delivery={"health": "degraded"},
         )
     encoded = encode_live_perception_result(
+        session_id="session-1",
+        session_generation=1,
         frame_index=0,
         source_frame_index=0,
         session_seconds=0.0,