REG-A04 — after (hash-pseudonymity boundary published; six blanket-confirmability clauses corrected)
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Row: REG-A04 [AEG2:8.1][GDPR] ARCH HIGH 'Hash pseudonymity' — SEED -> DOCUMENTED
Dependency: REG-012 (closed FIXED). UC-037's LEGAL-REVIEW-REQUIRED flag stays.

Premise, re-verified against source rather than trusted:
  $ sed -n '1807,1809p' aegis/core/crypto_audit.py
    
            if self._shredder is None or not subject_id:
                return sha256_hex(data)
  $ grep -n 'def digest' -A6 aegis/core/crypto_shredder.py | head -12
    244:    def digest(self, subject_id: str, data: bytes) -> str:
    245-        """Return a keyed digest of ``data`` that dies with ``subject_id``'s key.
    246-
    247-        Mechanism: the salt is ``HMAC(subject_key, "aegis-shred-digest-salt-v1")``
    248-        and the digest is ``HMAC(salt, data)``. The salt is *derived*, never
    249-        stored, so ``shred`` removing the one key row removes the salt with it.
    250-        A second stored secret would be a second thing to forget to delete.

  i.e. plain sha256_hex with shredding off (default) — confirmable; HMAC under a
  derived salt under v2 — confirmability dies with the key.

Six clauses asserted the old blanket claim. All corrected:
  1. docs/CLAIMS_MATRIX.md:137  CLM-068 boundary cell
     - 'still carries its request and response digests, so a guessed plaintext can
       be confirmed against them' -> scheme split
     - shredding_version enumeration named only v1 (contradicting CLM-098) -> v1 + v2
  2. docs/architecture/DECISIONS.md:185  AD-14 cost
  3. docs/institutional/DOC-02_CRYPTOGRAPHIC_FORENSIC_BLUEPRINT.md:200  (§6.2)
  4. docs/institutional/DOC-05_REGULATORY_DOSSIER.md:175  (§5.8.1)
  5. docs/FAQ_TECHNICAL.md:95
  6. (was already correct, left alone) docs/privacy/DATA_RETENTION.md:90, UC-037

New boundary row, in the destination the register's §1 requires:
  docs/institutional/UNSUPPORTED_CLAIMS.md — UC-044 'Evidence digests are
  anonymous data ...' with the blocked wording list and the LEGAL-REVIEW pointer.

  $ grep -c 'UC-044' docs/institutional/UNSUPPORTED_CLAIMS.md
    2

Doc-only. No code change; no legal conclusion asserted.

Gates re-run after the edits:
verify_docs: verify_docs: PASS (0 findings)
verify_claims: verify_claims: PASS (102 claims, 0 findings)
verify_links: verify_links: PASS (1285 relative links and anchors resolved)
verify_documentation --strict: status=PASS errors=0 warnings=0
