[AZ-297] C7 InferenceRuntime: Protocol + DTOs + factory

Freezes the c7_inference Public API per
_docs/02_document/contracts/c7_inference/inference_runtime_protocol.md
v1.0.0:

- InferenceRuntime Protocol (6 methods: compile_engine,
  deserialize_engine, infer, release_engine, thermal_state,
  current_runtime_label) in components/c7_inference/interface.py.
- DTOs (PrecisionMode enum, OptimizationProfile, BuildConfig,
  EngineCacheEntry, EngineHandle opaque marker) in _types/inference.py
  — placed at the L1 types layer so C10 can re-export EngineCacheEntry
  without crossing the components.* boundary (AZ-270 AC-6).
- ThermalState DTO expanded in _types/thermal.py from the AZ-355
  forward-declared stub to the AZ-297 contract shape (cpu/gpu temp,
  thermal_throttle_active, measured_clock_mhz, measured_at_ns,
  is_telemetry_available). Invariant I-6: when telemetry is
  unavailable, throttle is False.
- Error family rooted at c7_inference.errors.RuntimeError (9 subtypes:
  EngineBuildError, EngineDeserializeError, EngineHashMismatchError,
  EngineSchemaMismatchError, EngineSidecarMissingError,
  CalibrationCacheError, InferenceError, OutOfMemoryError,
  TelemetryUnavailableError). RuntimeNotAvailableError stays in
  runtime_root/errors.py — composition-time, outside the family.
- C7InferenceConfig per-component config block (runtime label,
  thermal_poll_hz, engine_cache_dir) with constructor-time validation
  rejecting unknown runtime labels.
- Composition-root factory build_inference_runtime in
  runtime_root/inference_factory.py with three BUILD_* gates
  (BUILD_TENSORRT_RUNTIME, BUILD_ONNX_TRT_EP_RUNTIME,
  BUILD_PYTORCH_FP16_RUNTIME). Concrete strategy modules are imported
  lazily via __import__ AFTER the flag check, so a Tier-0 build with
  the flag OFF MUST NOT load the strategy module (AC-5 / I-5;
  verifiable via sys.modules).
- 37 conformance tests cover all 8 ACs + NFR-perf-factory
  (p99 build under 200 ms × 1000 calls) + NFR-reliability-error-family.
  AC-8 introspects the contract file's Shape table and asserts method
  parity against the runtime Protocol; also asserts all 9 error
  subtypes are documented.

Retired the AZ-263 scaffolding EngineCacheEntry from _types/manifests.py
(replaced by the AZ-297 canonical shape in _types/inference.py); updated
the LightGlue-flavoured EngineHandle Protocol docstring in
_types/manifests.py to rationalize its intentional dual existence
with the C7 opaque EngineHandle (same name, different consumer-side
cut, mirroring the C4/C5 ISam2GraphHandle pattern).

Stale ThermalState.throttle docstring references in c4_pose/config.py,
c4_pose/interface.py, and _types/pose.py updated to
thermal_throttle_active.

Full unit-test sweep: 843 passed, 2 pre-existing environment skips
(cmake, actionlint).

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

src/gps_denied_onboard/components/c4_pose/config.py

@@ -34,7 +34,7 @@ class C4PoseConfig:
     * ``ransac_reprojection_threshold_px`` — RANSAC inlier-distance
       threshold. Default 4.0 pixels per the contract.
     * ``thermal_throttle_threshold_celsius`` — informational only;
-      the actual ``ThermalState.throttle`` decision is owned by C7
+      the actual ``ThermalState.thermal_throttle_active`` decision is owned by C7
       (AZ-302). Default 75.0 °C.
     """
 

src/gps_denied_onboard/components/c4_pose/interface.py

@@ -51,7 +51,7 @@ class PoseEstimator(Protocol):
     ) -> PoseEstimate:
         """Run PnP → factor add → covariance recovery.
 
-        Per-frame thermal decision: ``thermal_state.throttle == True``
+        Per-frame thermal decision: ``thermal_state.thermal_throttle_active == True``
         engages the Jacobian path (cheap, ~5-10 % accuracy loss);
         ``False`` engages the Marginals path (production default).