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

server/swagger/swagger.js

@@ -544,6 +544,15 @@ const doc = {
           t: { type: 'integer', description: 'Sample time, epoch ms.', example: 1783720000000 },
         },
       },
+      ShardOnlinePlayer: {
+        type: 'object',
+        description: 'A player online now (redacted for the public list).',
+        properties: {
+          serial: { type: 'string', example: '0x24C' },
+          name: { type: 'string', example: 'Darrow' },
+          map: { type: 'string', nullable: true, example: 'Trammel' },
+        },
+      },
       ShardHouse: {
         type: 'object',
         description: 'A house at its current decay stage.',