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

server/db/schema.sql

@@ -31,7 +31,7 @@ CREATE TABLE IF NOT EXISTS users (
   tokens_valid_after DATETIME NULL,
   created_at    DATETIME NOT NULL DEFAULT CURRENT_TIMESTAMP,
   last_login_at DATETIME NULL,
-  last_login_ip VARCHAR(45)  NULL           -- IPv6-capable; set on each login
+  last_login_ip VARCHAR(45)  NULL           -- IPv6-capable, set on each login
 ) ENGINE=InnoDB DEFAULT CHARSET=utf8mb4;
 
 CREATE TABLE IF NOT EXISTS posts (