Unify API auth + RFC-compliant CRL/OCSP (M-002 + M-003 + M-006, auto-closes M-001)

Closes the remaining P1 gaps from coverage-gap-audit.md (M-001/M-002/M-003/M-006)
on top of the C-001/C-002 ownership + agent-FK contract fixes landed in
a53a4b8. The work lands as a single commit spanning server, docs, tests,
and the React client.

M-002 — Named API keys with per-key actor propagation
  * Migration 000014 adds the 'api_keys' table (id, name, hash,
    principal, role, created_at, last_used_at, disabled_at) so every
    credential carries an identifiable principal instead of the
    opaque 'anonymous'/'api-key' sentinel.
  * Auth middleware now rotates through configured keys, performs
    constant-time hash comparison, stamps 'last_used_at', and emits
    an actor struct via contextWithActor(). The audit middleware,
    bulk-revocation handler, approval handlers, and MCP tool layer
    now read the principal off the context and persist it on every
    audit_events row.
  * Regression coverage:
      - internal/api/middleware/audit_test.go — actor propagation,
        principal redaction for disabled keys, anonymous fallback for
        unauthenticated endpoints.
      - internal/api/handler/bulk_revocation_handler_test.go,
        job_handler_test.go — principal-on-audit assertions.

M-003 — Authorization gates (Phase B)
  * Approval handler rejects self-approval / self-rejection with 403
    when the actor principal equals the job's requested_by field.
  * Bulk revocation is gated behind the 'admin' role; operators and
    viewers receive 403.
  * Regression coverage:
      - internal/service/job_test.go — TestApproveJob_NotSelf,
        TestRejectJob_NotSelf.
      - internal/api/handler/bulk_revocation_handler_test.go —
        TestBulkRevoke_RequiresAdmin, TestBulkRevoke_AdminSucceeds.

M-006 — RFC-compliant CRL/OCSP on the unauthenticated .well-known mux
  * Per RFC 8615, relying parties cannot reasonably be asked to
    authenticate against the issuing certctl instance to retrieve
    revocation material. CRL and OCSP move off the authenticated
    '/api/v1/crl*' and '/api/v1/ocsp/*' paths onto:
        GET /.well-known/pki/crl/{issuer_id}
            Content-Type: application/pkix-crl   (RFC 5280 §5)
        GET /.well-known/pki/ocsp/{issuer_id}/{serial}
            Content-Type: application/ocsp-response  (RFC 6960)
  * Non-standard JSON CRL shape is removed; only DER is served.
  * Short-lived certificate exemption (profile TTL < 1h → skip
    CRL/OCSP) is preserved; the response simply omits the serial.
  * Routes are registered on the unauthenticated 'finalHandler' mux
    in cmd/server/main.go alongside EST ('/.well-known/est/*') and
    SCEP ('/scep'). Legacy authenticated paths return 404.
  * Regression coverage:
      - internal/api/handler/certificate_handler_test.go — content
        type, DER parseability, 404 for unknown issuer.
      - internal/api/handler/adversarial_path_test.go — unauthenticated
        access asserted for CRL, OCSP, EST, SCEP.
      - internal/api/router/router_test.go — route-table assertion
        that '.well-known/pki/*', '.well-known/est/*', and '/scep' are
        mounted on the unauthenticated branch.

M-001 — Auto-closed by M-002
  EST and SCEP were already registered on the unauthenticated
  'finalHandler' mux; the router comment at
  internal/api/router/router.go:247 now matches reality. The
  adversarial-path tests above lock the behavior in.

Verification (all gates green):
  * go vet ./...                                           — clean
  * go build ./...                                         — ok
  * go test -short ./... (55+ packages)                    — all pass
  * web/ : npm test (225 Vitest tests)                     — all pass
  * web/ : npx tsc --noEmit                                — clean
  * grep sweep for '/api/v1/(crl|ocsp)' — 13 surviving hits,
    all intentional M-006 tombstone/relocation comments.

Documentation:
  * coverage-gap-audit.md — status flips M-001/M-002/M-003/M-006 →
    Fixed, with per-finding resolution paragraphs citing regression
    test IDs. (Audit file lives outside this repo; see cowork root.)
  * CLAUDE.md Project Status line updated with the auth-unification
    closure note.
  * docs/features.md, docs/architecture.md, docs/quickstart.md,
    docs/concepts.md, docs/connectors.md, docs/test-env.md,
    docs/testing-guide.md, docs/compliance-*.md, docs/demo-advanced.md
    — refreshed for the new '.well-known/pki/*' namespace and named
    API keys.
  * api/openapi.yaml — documents the new unauthenticated endpoints
    and removes the legacy '/api/v1/crl*' + '/api/v1/ocsp/*' paths.

.gitignore: adds '/.gocache/' and '/.gomodcache/' for the session-
scoped Go caches so they never enter the tree.

docs/concepts.md

@@ -216,9 +216,9 @@ certctl implements revocation using three complementary mechanisms:
 
 **Bulk Revocation** (Fleet-Level Incident Response): For large-scale incidents like CA compromise or team infrastructure decommissioning, `POST /api/v1/certificates/bulk-revoke` revokes all certificates matching filter criteria in a single operation. Filter by profile, owner, team, agent group, or issuer to target the affected certificate set. This is essential for incident response — instead of revoking certificates one-by-one, operators can revoke an entire fleet in minutes. Bulk revocation creates individual revocation jobs that reuse the existing revocation pipeline, ensuring every certificate is audited and notifications are sent.
 
-**Certificate Revocation List (CRL)**: certctl serves both a JSON-formatted CRL at `GET /api/v1/crl` and DER-encoded X.509 CRLs per issuer at `GET /api/v1/crl/{issuer_id}`. The DER CRL is signed by the issuing CA's key and has 24-hour validity — clients can download it periodically to check revocation status offline.
+**Certificate Revocation List (CRL)**: certctl serves DER-encoded X.509 CRLs per issuer at `GET /.well-known/pki/crl/{issuer_id}` (RFC 5280 §5 wire format, RFC 8615 well-known namespace). The endpoint is unauthenticated so any relying party — browser, TLS client, hardware appliance — can fetch it without a certctl API key. The CRL is signed by the issuing CA's key and has 24-hour validity; clients can download it periodically to check revocation status offline. The response carries `Content-Type: application/pkix-crl`.
 
-**OCSP Responder**: For real-time revocation checking, certctl includes an embedded OCSP responder at `GET /api/v1/ocsp/{issuer_id}/{serial}`. It returns signed OCSP responses (good, revoked, or unknown) so clients can verify certificate status without downloading the full CRL.
+**OCSP Responder**: For real-time revocation checking, certctl includes an embedded OCSP responder at `GET /.well-known/pki/ocsp/{issuer_id}/{serial}` (RFC 6960). Like the CRL endpoint, it is unauthenticated and returns signed OCSP responses (good, revoked, or unknown) with `Content-Type: application/ocsp-response`, so clients can verify certificate status without downloading the full CRL.
 
 Short-lived certificates (those assigned to profiles with TTL under 1 hour) are exempt from CRL and OCSP — their rapid expiry is considered sufficient revocation. This is a deliberate design choice to reduce infrastructure overhead for ephemeral machine-to-machine credentials.