[AZ-611] Add --skip-auto-sync flag to bypass AC-9 validator

Mid-flight fixtures (Derkachi) and stationary-still scenarios
(FT-P-01) have no take-off spike for the IMU detector and produce
false-positive video motion onsets, so the AC-9 frame-window
validator rejects every plausible offset. Add an operator-acknowledged
opt-out: a new ReplayConfig.skip_auto_sync_validation flag that
suppresses validation, paired with a hard requirement that
time_offset_ms also be set (silent-zero guard at both schema and
adapter layers).

Wired through schema -> CLI (--skip-auto-sync) -> composition root
-> ReplayInputAdapter; Derkachi e2e fixture now passes
time_offset_ms=0 + skip_auto_sync=True by default since the synth
tlog and the video share the same t=0 anchor by construction.

5 new unit tests:
  * schema gate rejects skip=True without manual offset
  * schema gate accepts the legal pair
  * default field value is False (default-construction safety)
  * adapter constructor mirrors the schema gate
  * adapter open() bypasses validate_offset_or_fail when flag is set

All 38 unit tests in test_az401 + test_az405 pass on Mac.

Co-authored-by: Cursor <cursoragent@cursor.com>

tests/unit/replay_input/test_az405_replay_input_adapter.py

@@ -610,6 +610,81 @@ def test_ac7_ac8_validator_hard_fail_raises_on_open(
         adapter.open()
 
 
+# ---------------------------------------------------------------------
+# AZ-611 — skip_auto_sync_validation bypasses the AC-9 validator
+
+
+def test_az611_skip_auto_sync_validation_bypasses_ac9(
+    synthetic_video: Path,
+    synthetic_tlog_path: Path,
+    camera_calibration: CameraCalibration,
+    fake_wgs_converter: mock.MagicMock,
+    fake_fdr_client: mock.MagicMock,
+) -> None:
+    """A manual offset that WOULD hard-fail AC-9 succeeds when the
+    operator explicitly opts out via ``skip_auto_sync_validation=True``.
+    Mirrors the AC-7 hard-fail scenario above so the bypass is the
+    only variable.
+    """
+    # Arrange — same manual offset (60 s) that AC-7 above proves
+    # pushes every frame outside the IMU window.
+    messages = _build_takeoff_messages()
+    adapter = ReplayInputAdapter(
+        video_path=synthetic_video,
+        tlog_path=synthetic_tlog_path,
+        camera_calibration=camera_calibration,
+        target_fc_dialect=FcKind.ARDUPILOT_PLANE,
+        wgs_converter=fake_wgs_converter,
+        fdr_client=fake_fdr_client,
+        pace=ReplayPace.ASAP,
+        manual_time_offset_ms=60_000,
+        skip_auto_sync_validation=True,
+        auto_sync_config=AutoSyncConfig(),
+        tlog_source_factory=_factory_for(messages),
+        video_timestamps_factory=_video_timestamps_factory(),
+    )
+
+    # Act
+    try:
+        bundle = adapter.open()
+
+        # Assert — the bypass let the open() complete with the manual
+        # offset intact, even though the validator would have rejected it.
+        assert bundle.resolved_time_offset_ms == 60_000
+        assert bundle.auto_sync_result is None
+    finally:
+        adapter.close()
+
+
+def test_az611_skip_auto_sync_validation_requires_manual_offset(
+    synthetic_video: Path,
+    synthetic_tlog_path: Path,
+    camera_calibration: CameraCalibration,
+    fake_wgs_converter: mock.MagicMock,
+    fake_fdr_client: mock.MagicMock,
+) -> None:
+    """Constructor refuses ``skip_auto_sync_validation=True`` paired
+    with ``manual_time_offset_ms=None`` (silent-zero guard).
+    """
+    # Act / Assert
+    with pytest.raises(
+        ReplayInputAdapterError,
+        match=r"skip_auto_sync_validation=True requires.*manual_time_offset_ms",
+    ):
+        ReplayInputAdapter(
+            video_path=synthetic_video,
+            tlog_path=synthetic_tlog_path,
+            camera_calibration=camera_calibration,
+            target_fc_dialect=FcKind.ARDUPILOT_PLANE,
+            wgs_converter=fake_wgs_converter,
+            fdr_client=fake_fdr_client,
+            pace=ReplayPace.ASAP,
+            manual_time_offset_ms=None,
+            skip_auto_sync_validation=True,
+            auto_sync_config=AutoSyncConfig(),
+        )
+
+
 # ---------------------------------------------------------------------
 # AC-6 — low combined confidence WARN-and-proceed