Add player portal + character-sheet front end (phase 4 follow-up)

Turns the raw shard endpoints into proper, navigable pages in the site's visual
language.

- components/CharacterSheet.jsx: reusable sheet — attribute tiles, vitals bars,
  resistances, skills (with bars), and equipment — styled with the shared
  panel/grid vocabulary.
- Player portal with a nav bar: PlayerPortalLayout (Characters / Account tabs +
  sign-out) wraps /player and /account. /player (PlayerCharacters) tells the
  logged-in player if they haven't linked a game account (with the [link code
  prompt) or, once linked, shows their characters grouped by account; each
  character opens its sheet at /player/char/:serial. Account security moved into
  the same shell (the buried "Game accounts" block was removed from it).
  Login/register now land on /player.
- Public: GET /public/shard/online (redacted name+serial+map) drives an
  "Online now" list on /site/shard that links to public character sheets at
  /site/shard/char/:serial (ShardChar). Swagger: ShardOnlinePlayer + regenerated.
- api.shard.online added.

Verified live against the running shard: Darrow's full sheet (STR 120, 58
skills, 3 equipment) renders through the browser-facing proxy; the online list
returns the live roster; player routes 401 without a session.

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_011qPmpmVH1xGCiZoz9m9vW3

client/src/routes/player/PlayerLogin.jsx

@@ -20,7 +20,7 @@ export default function PlayerLogin() {
   const { user, login, loginTotp, ssoLoginTotp } = useAuth()
   const navigate = useNavigate()
   const location = useLocation()
-  const dest = location.state?.from?.pathname || '/account'
+  const dest = location.state?.from?.pathname || '/player'
   // A staff member who signs in here belongs in the admin shell, not the portal.
   const destFor = (u) => (u && u.role !== 'player' ? '/admin' : dest)