Player accounts frontend + Swagger + schema comment fix

- Player portal: RequirePlayer guard, /account routes (login, register,
  settings) with shared PlayerShell; register reads /public/settings derived
  flags; AuthContext.register; api.register + api.player.* namespace.
- Admin UI: player role + status/email + reset-password hint in UserEditor,
  status column + badge-player in UsersAdmin, player_registration select in
  SettingsAdmin; 'disabled' SSO error copy.
- Swagger: Player tag + RegisterRequest/ChangeUsername/ChangePassword/
  PlayerAccount/OkFlag schemas; regenerated swagger-output.json.
- Fix: remove a semicolon from a schema.sql inline comment that broke the
  statement splitter in ensureSchema.

Verified against the live dev DB: schema migrations apply (player enum,
nullable password_hash, email/status/last_login_ip, seeded setting); 21-check
controller smoke (register gating, dup/reserved, null-hash rules, self change
username/password with session re-issue surviving the cutoff, SSO-only initial
password, banned-login refusal); case-insensitive uniqueness; public settings
expose only derived registration flags. Client builds; 133 server tests green.

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_019rao86n5cXpwAyjdBFEshV

client/src/routes/admin/AdminLogin.jsx

@@ -8,6 +8,7 @@ import { api } from '../../api/client.js'
 // Friendly copy for the ?sso_error codes the SSO callback can redirect back with.
 const SSO_ERRORS = {
   not_linked: 'That account is not linked to an admin user. Sign in with your password, then link it under Account.',
+  disabled: 'This account is not active. Contact an administrator.',
   denied: 'Sign-in was cancelled.',
   unavailable: 'That sign-in method is not available right now.',
   bad_state: 'Your sign-in session expired. Please try again.',