phase 1.6: lock Gate 3b = C, reconcile docs to shipped state, fix double-upload file leak

Four threads landing together — all driven by the audit J asked for before
production cutover.

(1) Gate 3b DECIDED: Option C (defer classifications). `BiometricCollection.classifications`
    stays `Option<JSON> = None` in v1. `docs/specs/GATE_3B_DEEPFACE_DESIGN.md` status
    flipped from "draft / awaits product" to DECIDED. Consent template + retention
    schedule revised to remove all "automated facial-classification" / "deepface"
    language so disclosed scope matches implemented scope.

(2) Endpoint-path drift reconciled across 3 docs. `PHASE_1_6_BIPA_GATES.md`,
    `BIPA_DESTRUCTION_RUNBOOK.md`, and `biometric_retention_schedule_v1.md` had
    references to legacy `/v1/identity/subjects/*` paths (proposed under a separate
    identityd daemon, never shipped) — corrected to actual shipped routes
    `/biometric/subject/*` (catalogd-local). Schema block in PHASE_1_6_BIPA_GATES
    rewritten to reflect JSON `SubjectManifest.biometric_collection` substrate
    (not the proposed Postgres `subjects` table).

(3) New operational artifacts:
    - `scripts/staffing/verify_biometric_erasure.sh` — checks 4 things post-erasure
      (manifest cleared, uploads dir empty, audit row matches, chain verified).
      Smoke-tested live against WORKER-2.
    - `scripts/staffing/biometric_destruction_report.sh` — monthly anonymized
      destruction-event aggregation. Smoke-tested clean.
    - `scripts/staffing/bundle_counsel_packet.sh` — tarballs the counsel-review
      packet with per-file SHA-256 manifest.
    - `docs/runbooks/LEGAL_AUDIT_KEY_ROTATION.md` — formal rotation procedure
      operationalized after the 2026-05-05 /tmp wipe incident.
    - `docs/counsel/COUNSEL_REVIEW_PACKET_2026-05-05.md` — cover note bundling
      all eng-staged BIPA docs for counsel review with per-doc questions, sign-off
      checklist, recommended review sequence.

(4) Double-upload file leak fixed in `crates/catalogd/src/biometric_endpoint.rs`.
    `verify_biometric_erasure.sh` smoked WORKER-2 and surfaced a stranded photo
    file. Investigation showed the file was 13-byte test-fixture bytes (zero PII,
    no biometric content); audit timeline showed two consecutive uploads followed
    by one erasure — the second upload had silently overwritten manifest.data_path,
    orphaning the first file. Patched `process_upload` to refuse a second upload
    with HTTP 409 + `error: "biometric_already_collected"` when
    `biometric_collection.is_some()` on the manifest. Operator must explicitly
    POST `/biometric/subject/{id}/erase` first.

    Tests: new `second_upload_without_erase_returns_409` (asserts 409 + manifest
    pointer unchanged + first file untouched on disk). Replaced
    `repeated_uploads_grow_the_chain` with `upload_erase_upload_grows_the_chain_cleanly`
    (covers the legitimate re-collection cycle: chain grows to 3 rows). Updated
    `content_type_with_parameters_accepted` to use 2 distinct subjects (was
    using 1 subject with 2 uploads to test ct parsing — would now 409).

    22/22 biometric_endpoint tests + 59/59 catalogd lib tests green post-patch.

Production posture: gateway needs `cargo build --release -p gateway` +
`systemctl restart lakehouse.service` to pick up the new 409 in live traffic.

Counsel calendar is now the only remaining blocker for first real-photo intake.

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

docs/specs/GATE_3B_DEEPFACE_DESIGN.md

@@ -1,6 +1,8 @@
 # Gate 3b — Deepface Classification Integration (Design)
 
-**Status:** Design draft — 2026-05-03 morning · **Companion to:** [`PHASE_1_6_BIPA_GATES.md`](../PHASE_1_6_BIPA_GATES.md) Gate 3 · **Depends on:** Gate 3a (photo upload) which is shipped (`f1fa6e4`)
+**Status:** **DECIDED 2026-05-05 — Option C (defer classifications)** · Original design draft 2026-05-03 morning · **Companion to:** [`PHASE_1_6_BIPA_GATES.md`](../PHASE_1_6_BIPA_GATES.md) Gate 3 · **Depends on:** Gate 3a (photo upload) which is shipped (`f1fa6e4`)
+
+> **Decision summary (2026-05-05):** J accepted Option C. `BiometricCollection.classifications` remains `Option<JSON> = None` in v1. The consent template and retention schedule were revised the same day to remove all "automated facial-classification" language so the disclosed scope matches the implemented scope. If a real product requirement for classifications surfaces later, this doc's Option A (Python subprocess) or Option B (ONNX-in-Rust) is picked up under a v2 consent template + v2 retention schedule.
 
 > **What this is.** Three options for how `BiometricCollection.classifications` (currently `Option<JSON>`, always `None`) gets populated by an automated facial-attribute classifier. Phase 1.6 Gate 3a ships the consent-gated upload + audit chain + transactional rollback; Gate 3b adds the classification step. The substrate is ready — what's missing is the design choice for HOW classification happens.
 >
@@ -152,6 +154,8 @@ Reasoning:
 
 ⚖ J — pick A / B / C. The substrate accommodates any choice; the cost is the design-doc → counsel-coordination → engineering loop, which differs by an order of magnitude across the options.
 
+**[2026-05-05] J's decision: Option C.** Reasoning recorded in change log below. Consent + retention doc revisions for Option C shipped same day; counsel review of revised text is the remaining work.
+
 ---
 
 ## Open questions for J