[AZ-381] C5 StateEstimator protocol + factory + C8 DTO reshape

- Add StateEstimator Protocol (6 methods, @runtime_checkable) + DTOs
  (EstimatorOutput, EstimatorHealth, IsamState, PoseSourceLabel, Quat)
  in _types/state.py per state_estimator_protocol.md v1.0.0.
- Add C5 error hierarchy (StateEstimatorError + 3 subclasses) and
  C5StateConfig (strategy, keyframe_window, spoof gates,
  no_estimate_fallback_s) with __post_init__ validation.
- Add ISam2GraphHandle Protocol + ISam2GraphHandleImpl skeleton (all
  4 methods raise NotImplementedError naming AZ-382 as owner).
- Add build_state_estimator factory + bind_state_ingest_thread for
  single-writer enforcement; ADR-002 build-flag gating
  (BUILD_STATE_<variant>); INFO log on success.
- Strict reshape of legacy EstimatorOutput / EstimatorHealth across
  all 6 C8 production files (_outbound_provenance,
  _covariance_projector, pymavlink_ardupilot_adapter,
  msp2_inav_adapter, mavlink_gcs_adapter, interface) + 6 C8 test
  files (UUID frame_id, LatLonAlt position_wgs84, Quat orientation,
  PoseSourceLabel enum source_label). Remove ad-hoc DTOs from
  _types/pose.py and from C4's public __init__ (EstimatorOutput is a
  C5 concept, not a C4 one).
- 20 AZ-381 AC tests (10 ACs + 4 config range + NFR + conformance).
- Full suite: 521 passed, 2 skipped (+20 vs Batch 11).
- Contracts: state_estimator_protocol.md v1.0.0 -> active;
  composition_root_protocol.md v1.2.0 -> v1.3.0 (additive state
  block + factory + ingest-thread binding).
- Impl report: _docs/03_implementation/batch_12_cycle1_report.md.

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

_docs/02_document/contracts/c5_state/state_estimator_protocol.md

@@ -4,8 +4,8 @@
 **Producer task**: AZ-381 (Protocol + DTOs + factory + composition + concrete `ISam2GraphHandle`)
 **Consumer tasks**: AZ-382 (iSAM2 + IncrementalFixedLagSmoother wiring), AZ-383 (Factor adds), AZ-384 (Marginals + outputs), AZ-385 (Source-label + spoof gate), AZ-386 (ESKF baseline), AZ-387 (Smoothed history → FDR), AZ-388 (AC-5.2 fallback), AZ-389 (Orthorectifier → C6).
 **Version**: 1.0.0
-**Status**: draft
-**Last Updated**: 2026-05-10
+**Status**: active
+**Last Updated**: 2026-05-11
 **Module-layout home**: `src/gps_denied_onboard/components/c5_state/interface.py`, `src/gps_denied_onboard/components/c5_state/__init__.py`, `src/gps_denied_onboard/runtime_root/state_factory.py`
 
 ## Purpose

_docs/02_document/contracts/shared_config/composition_root_protocol.md

@@ -3,7 +3,7 @@
 **Component**: shared_config (cross-cutting concern owned by E-CC-CONF / AZ-246)
 **Producer tasks**: AZ-269 (config loader + outer Config) and AZ-270 (compose_root + compose_operator + StrategyNotLinkedError)
 **Consumer tasks**: every component task that takes a config block; `runtime_root.py` and `operator_tool/__main__.py` (the two composition-root entrypoints)
-**Version**: 1.2.0
+**Version**: 1.3.0
 **Status**: draft
 **Last Updated**: 2026-05-11
 
@@ -120,3 +120,4 @@ change (AC-NEW-3 / RESTRICT-UAV-4).
 | 1.0.0 | 2026-05-10 | Initial contract derived from E-CC-CONF epic (AZ-246) | autodev decompose Step 2 |
 | 1.1.0 | 2026-05-11 | Add takeoff sequence section + `EXIT_FDR_OPEN_FAILURE` (AZ-296) | autodev batch 7 |
 | 1.2.0 | 2026-05-11 | Add cross-cutting `fc` (`FcConfig`) and `gcs` (`GcsConfig`) blocks + `build_fc_adapter` / `build_gcs_adapter` factories + outbound-thread single-writer binding (AZ-390) | autodev batch 8 |
+| 1.3.0 | 2026-05-11 | Add `state` (`C5StateConfig`) block + `build_state_estimator(config, *, imu_preintegrator, se3_utils, wgs_converter, fdr_client) -> (StateEstimator, ISam2GraphHandle)` factory + state-ingest-thread single-writer binding (`bind_state_ingest_thread`); state factory MUST be invoked BEFORE C4 `build_pose_estimator` so the returned `ISam2GraphHandle` can be injected into C4 (AZ-381) | autodev batch 12 |