[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/_autodev_state.md

@@ -6,9 +6,9 @@ step: 13
 name: Update Docs
 status: in_progress
 sub_step:
-  phase: 6
+  phase: 8
   name: component-doc-updates
-  detail: "batch 3 next: c6/c7/c8; then c10/c11/c12/c13; then 8 helpers; then tests/"
+  detail: "batch 3/~5 done (c6/c7/c8); next: c10/c11/c12/c13; then 8 helpers; then tests/"
 retry_count: 0
 cycle: 1
 tracker: jira