feat(api): sign-in, refresh rotation and bootstrap admin (M1)

- users, refresh_tokens and audit_log schema (migration 00002)
- argon2id passwords with rehash on login, password policy, lockout
  with exponential back-off and a per-IP rate limit in Redis
- Ed25519 JWT access tokens with kid-based key rotation; rotating
  refresh tokens with reuse detection (cookie for web, body for Android)
- bootstrap admin on first start; must_change_credentials and
  must_change_password gate every other endpoint
- /auth/login, /auth/refresh, /auth/logout(-all), /me, /me/password,
  /me/bootstrap-credentials, /me/sessions; server-info reports
  bootstrap_required
- role policy from docs/auth-and-roles.md with table tests
- problem+json errors with field errors; ru/en translations of the codes
- install.sh and update.sh generate JWT_PRIVATE_KEY

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

packages/i18n/locales/en/errors.json

@@ -0,0 +1,39 @@
+{
+  "common": {
+    "internal": "Something went wrong on the server. Please try again",
+    "bad_request": "Invalid request",
+    "not_found": "Not found",
+    "method_not_allowed": "This action is not supported"
+  },
+  "auth": {
+    "invalid_credentials": "Wrong username or password",
+    "too_many_attempts": "Too many sign-in attempts. Please wait a bit",
+    "user_blocked": "This account is blocked. Contact your administrator",
+    "unauthorized": "Sign in to continue",
+    "token_expired": "Your session has expired, please sign in again",
+    "token_invalid": "Your session is invalid, please sign in again",
+    "token_revoked": "Your session has ended, please sign in again",
+    "refresh_invalid": "Your session has ended, please sign in again",
+    "refresh_reused": "Your session was ended for security reasons, please sign in again",
+    "refresh_race": "Your session is being refreshed, please retry",
+    "credentials_change_required": "Change the administrator username and password first",
+    "password_change_required": "Change your temporary password first",
+    "current_password_required": "Enter your current password",
+    "current_password_invalid": "The current password is wrong",
+    "bootstrap_not_required": "The administrator credentials have already been changed",
+    "session_not_found": "Session not found"
+  },
+  "validation": {
+    "password_too_short": "The password must be at least {{min}} characters",
+    "password_too_long": "The password must be at most {{max}} characters",
+    "password_same_as_username": "The password must not match the username",
+    "password_too_common": "This password is too common — choose another one",
+    "password_unchanged": "The new password must differ from the current one",
+    "username_invalid": "Username: {{min}} to {{max}} characters — Latin letters, digits, \".\", \"_\", \"-\"",
+    "username_taken": "This username is already taken",
+    "locale_unsupported": "This language is not supported",
+    "display_name_too_long": "The name must be at most {{max}} characters",
+    "ui_prefs_invalid": "Invalid setting value",
+    "client_type_invalid": "Unknown app type"
+  }
+}