[AZ-325] C10 CacheProvisioner orchestrator

Implements the public top-level F1 build orchestrator for E-C10 per
contract v1.1.0. Composes EngineCompiler (AZ-321), DescriptorBatcher
(AZ-322), and ManifestBuilder (AZ-323) into a single idempotent
operation guarded by a fcntl-backed cache_root/.c10.lock and a
post-build coverage walk.

Adds:
- CacheProvisionerImpl + FilelockFileLockFactory (provisioner.py)
- BuildRequest/BuildReport/BuildOutcome/SectorClassification DTOs +
  FileLockFactory Protocol + replaced placeholder CacheProvisioner
  Protocol with v1.1.0 surface (interface.py)
- C10ProvisionerConfig wired into C10ProvisioningConfig (config.py)
- BuildLockHeldError + ManifestCoverageError (errors.py)
- build_cache_provisioner composition root (c10_factory.py)
- 18 tests covering AC-1..AC-16 + NFR-perf-coverage-walk
- filelock>=3.13,<4.0 (single new third-party dep)

Idempotence (CP-INV-1) reuses AZ-323's _compute_manifest_hash /
_aggregate_tile_hash so the build-identity decision agrees byte-for-
byte with the Manifest's recorded manifest_hash. Coverage rollback
uses a .prev rename snapshot. Diagnostic compile_engines_for_corpus
is lock-free per AC-10.

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

_docs/_autodev_state.md

@@ -8,9 +8,9 @@ status: in_progress
 sub_step:
   phase: 1
   name: parse-tasks
-  detail: "batch 37: AZ-325 solo (3pt, C10 CacheProvisioner orchestrator); cumulative 34-36 PASS_WITH_WARNINGS"
+  detail: ""
 retry_count: 0
 cycle: 1
 tracker: jira
-last_completed_batch: 36
+last_completed_batch: 37
 last_cumulative_review: batches_34-36