Replaces AZ-382 NotImplementedError placeholders with real GTSAM factor
adds wired against the iSAM2 graph handle:
- add_vio -> BetweenFactorPose3 between consecutive VIO pose keys
(first call primes the chain; AZ-388 owns first-keyframe seeding).
- add_pose_anchor -> mode-dispatch per pose.covariance_mode:
"marginals" -> PriorFactorPose3 + handle.update();
"jacobian" -> skip iSAM2 add per AZ-361 contract.
Both paths bump _last_anchor_ns via time.monotonic_ns().
- add_fc_imu -> shared ImuPreintegrator.integrate_window +
reset_for_new_keyframe; builds a CombinedImuFactor between the
prev/curr (X, V, B) keyframe triple. Introduces new 'v' (velocity)
and 'b' (bias) GTSAM key namespaces decoupled from the VIO/pose
frame_id mapping.
Invariant 2 - non-decreasing timestamps - enforced per call with
EstimatorDegradedError + c5.state.out_of_order log. Every successful
add emits a structured DEBUG *_ok log; every failure emits a
structured ERROR *_failed log and raises through the C5 error
hierarchy (R05).
Contract-vs-reality fix-ups also landed:
- StateEstimator Protocol: add_fc_imu(ImuWindow) - was incorrectly
annotated as ImuTelemetrySample by AZ-381.
- _last_anchor_ns semantics switched to monotonic_ns() to match
last_anchor_age_ms.
- create() factory back-wires the ISam2GraphHandle to the estimator
via the new attach_handle() method.
Tests: +21 in tests/unit/c5_state/test_az383_factor_adds.py covering
all 8 ACs with mock ISam2GraphHandle instances. Three obsolete
AZ-382 tests (test_ac10_add_*_raises_named_az383) removed. Full
suite: 565 passed, 2 skipped.
Co-authored-by: Cursor <cursoragent@cursor.com>