[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>

src/gps_denied_onboard/runtime_root/_replay_branch.py

@@ -225,6 +225,7 @@ def _build_replay_input_bundle(
             fdr_client=fdr_client,
             pace=pace,
             manual_time_offset_ms=config.replay.time_offset_ms,
+            skip_auto_sync_validation=config.replay.skip_auto_sync_validation,
             auto_sync_config=auto_sync,
             mavlink_transport=mavlink_transport,
         )