[autodev] Step 13 partial: c6/c7/c8 cycle-1 doc sync

Batch 3 of the cycle-1 component-doc sync. For each of C6
(tile_cache), C7 (inference), C8 (fc_adapter):

- Append "Cycle-1 operational reality" paragraph to § 1
  documenting the actual cycle-1 wiring path:
  - C6: infrastructure seeded via build_pre_constructed's
    c6_descriptor_index (BUILD_FAISS_INDEX-gated) and
    c6_tile_store slots; no _STRATEGY_REGISTRY slot;
    AZ-687 replay-mode guard skips both seeds when the
    minimal replay Config omits the c6_tile_cache block.
  - C7: single InferenceRuntime built once via
    _build_c7_inference, identity-shared as the engine
    source for c3_lightglue_runtime (AZ-622 phase D);
    C7_AIRBORNE_BUILD_FLAGS lists tensorrt (production-
    default) + pytorch_fp16 (Tier-0 fallback);
    onnx_trt_ep deliberately omitted from airborne flags;
    AZ-687 replay-mode guard cascades to c3_lightglue_runtime.
  - C8: composed via a SEPARATE registry path
    (runtime_root/fc_factory.py) with its own _FC_REGISTRY
    + _GCS_REGISTRY; per-binary bootstrap modules register
    concrete strategies under BUILD_FC_* / BUILD_GCS_*
    flags; bind_outbound_emit_thread enforces the
    single-writer outbound invariant (AC-6).

- Add "Cycle-1 Tier-2 follow-up dependencies" subsection
  in § 7 of C7 only: onnx_trt_ep is implemented and the
  inference_factory recognises BUILD_ONNX_TRT_EP_RUNTIME,
  but airborne config selecting it raises a clean
  AirborneBootstrapError pointing only at the two airborne
  options. C6 and C8 have no parked Tier-2 strategies for
  cycle-1.

None of c6/c7/c8 import cv2 directly, so no OpenCV pin
row is added to § 5 (D-CROSS-CVE-1 leftover stays as it
is; the relaxed pin is recorded against c2.5/c3/c3.5/c4/c5
where the imports actually live).

Also refresh the D-CROSS-CVE-1 leftover replay timestamp
(condition still upstream-gated: gtsam wheels remain
numpy<2) and bump the autodev state's sub_step.detail to
record "batch 3/~5 done (c6/c7/c8); 4 components + 8
helpers + tests/ remain".

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

_docs/02_document/components/10_c8_fc_adapter/description.md

@@ -6,6 +6,8 @@
 
 **Architectural Pattern**: Strategy — `FcAdapter` interface with two concrete implementations: `PymavlinkArdupilotAdapter`, `Msp2InavAdapter`. Plus a `GcsAdapter` (single concrete `QgcTelemetryAdapter` today). All selected at startup by config (ADR-001), build-time gating per `BUILD_*` flags (ADR-002, both adapters typically linked into the deployment binary so a single image can target both FCs by configuration), composition-root wired (ADR-009).
 
+**Cycle-1 operational reality**: C8 is composed via a **separate registry path** from the rest of the strategy-selecting components — there is no `c8_fc_adapter` slot in the central `_STRATEGY_REGISTRY` populated by `register_airborne_strategies()` (AZ-591), and no `c8_*` row in `AIRBORNE_REQUIRED_PRE_CONSTRUCTED_KEYS`. Instead `runtime_root/fc_factory.py` owns two private registries — `_FC_REGISTRY` and `_GCS_REGISTRY` — and exposes `register_fc_adapter()` / `register_gcs_adapter()` so per-binary bootstrap modules (one per `BUILD_FC_<VARIANT>` / `BUILD_GCS_<VARIANT>` combination) can lazy-link the concrete adapter classes ahead of `build_fc_adapter()` / `build_gcs_adapter()`. Both calls run the build-flag gate against `_FC_BUILD_FLAGS = {"ardupilot_plane": "BUILD_FC_ARDUPILOT_PLANE", "inav": "BUILD_FC_INAV"}` and `_GCS_BUILD_FLAGS = {"qgc_mavlink": "BUILD_GCS_QGC_MAVLINK"}` and surface an OFF flag as `FcAdapterConfigError` / `GcsAdapterConfigError` naming the disabled flag (AC-4). The outbound single-writer invariant is enforced by `bind_outbound_emit_thread()` — called once per process before wiring outbound emit, a second call from any other thread raises `OutboundThreadAlreadyBoundError` (AC-6 / Invariant 8). Unit-test isolation uses `clear_strategy_registries()` + `clear_outbound_thread_binding()`. C8 takes **no** infrastructure dependency on `pre_constructed`; its `**deps` kwargs are populated by `compose_root`'s C5 / C13 wiring path (per-binary `main()` constructs the concrete adapter with the FC's port config and the C5 estimator's outbound `EstimatorOutput` stream).
+
 **Upstream dependencies**:
 - C5 StateEstimator → `EstimatorOutput` (5 Hz periodic emit driver).
 - Hardware: UART/USB to FC; UART (or USB) to GCS (often shared or via FC mavlink-routing).