feat(auth): TOTP setup endpoint, recovery codes, passkeys and master key rotation

- GET /auth/totp/setup returns the pending secret and otpauth URL (created
  on first call, reused on refresh) for the console to render as a QR code.
- Enabling TOTP issues 8 one-time recovery codes (argon2id hashes in
  admin_recovery_code); login accepts recoveryCode in place of totpCode,
  disable accepts either, and recovery_codes regenerates with the password.
- Passkeys via @simplewebauthn/server: register/list/rename/delete under
  the console session, public login options/verify that reuse the login
  rate limit and session cookies. Challenges are one-time rows in
  webauthn_challenge; RP ID and origins come from WEBAUTHN_RP_ID /
  WEBAUTHN_ORIGINS, falling back to the request host. Signature counter
  regressions are rejected. SessionInfo gains passkeyEnabled.
- --role rotate-master-key re-encrypts the secret table from
  SECRET_MASTER_KEY to SECRET_MASTER_KEY_NEW one row per transaction,
  skips rows already on the new key (resumable, swap keys to roll back),
  logs progress and audits secret.master_key_rotate. Secrets now record
  the master key fingerprint in kdf_params.kid.
- Runbook: recovery codes, passkey configuration, rotation steps and
  rollback.

Co-Authored-By: Claude Opus 5.5 <[email protected]>

deno.json

@@ -20,6 +20,7 @@
     "@earendil-works/pi-ai": "npm:@earendil-works/[email protected]",
     "@earendil-works/pi-ai/": "npm:/@earendil-works/[email protected]/",
     "@hono/swagger-ui": "npm:@hono/[email protected]",
+    "@simplewebauthn/server": "npm:@simplewebauthn/[email protected]",
     "@hono/zod-openapi": "npm:@hono/[email protected]",
     "@types/node": "npm:@types/[email protected]",
     "@types/nunjucks": "npm:@types/[email protected]",