refactor(server): split public, player and residual auth into capability routers (PR 5)

The last split PR of docs/website/API_V2_PLAN.md § Phase 2. public.routes.js,
player.routes.js and auth.routes.js are deleted; each group is now a directory
whose index.js owns the group gate and the mount table and declares no routes.
Every one of the 200 manifest routes is now in a capability router.

  public/  posts (2) wiki (4) pages (2) shard (12) site (4, group root)
  player/  account (8) shard (8) appeals (4), behind noindex + requireAuth
  auth/    login (2) register (1) invite (2) password (3) session (2, root)

No URL moves. All four gates zero-diff: routes.manifest.json (200 public + 2
internal), routes.guards.json, swagger-output.json (198 operations), and
docs/website/api-route-inventory.json was already in sync. 434 tests green.

Notes on the non-mechanical parts:

- public/index.js and auth/index.js carry no group gate, deliberately, and say
  so. The public surface is anonymous by contract (logged-out SPA, Discord bot,
  Android ShardStreamClient on /public/shard/stream); /auth is where a caller
  becomes authenticated. player/index.js gates on requireAuth only, never
  requireRole('player') — staff are a superset of players.
- GET /auth/me has a mount-order dependency: use('/me', meRouter) matches the
  bare /me, so the request runs meRouter's noindex + requireAuth and falls
  through. session.router.js must stay mounted last. Verified by the
  counterfactual — mounting it first still 401s but drops X-Robots-Tag, which
  no manifest or guards file can see.
- loginGuards moved to auth/loginGuards.js (frozen) rather than being copied
  into the three routers that spread it; sso.routes.js drops its duplicate.
- The :param shadowing check was re-run in dispatch order against the built
  stack: 86 routes, 64 literal, none shadowed. /public/wiki/{categories,tags}
  ahead of /:slug is the only ordering-sensitive pair.

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

server/src/router/v1/player/index.js

@@ -0,0 +1,43 @@
+// /api/v1/player — the player self-service surface, assembled from
+// per-capability routers.
+//
+// This file owns exactly two things: the gate every player route shares, and the
+// mount table. No route is declared here. Each capability router mounts at the
+// prefix it already owned inside the old monolithic player.routes.js, so the
+// emitted URL set is byte-identical — proved by a zero-line diff in
+// server/routes.manifest.json (`npm run routes:manifest`).
+//
+// **Staff are a superset of players.** This group is open to any authenticated
+// account, not just role 'player': every read/write is self-scoped to req.user.id,
+// and a staff member has every player ability plus their staff tools on top.
+// Adding a requireRole('player') here would 403 an admin off their own characters
+// (it happened once — see docs/website/BACKEND_DESIGN.md). Staff also reach the
+// identical self-scoped handlers under /admin/shard and /auth/me/account; those
+// are alternative URLs onto the same controllers, not duplicated logic.
+//
+// See docs/website/API_V2_PLAN.md § Phase 2 for the split.
+
+const express = require('express')
+
+const { requireAuth } = require('../../../auth/session.middleware')
+const noindex = require('../../../middleware/noindex')
+
+const accountRouter = require('./account.router')
+const shardRouter = require('./shard.router')
+const appealsRouter = require('./appeals.router')
+
+const playerRouter = express.Router()
+
+// Group gate: authenticated only (no role restriction). Keep it out of search
+// indexes. requireAuth also enforces the account status check (a disabled/banned
+// account is rejected here with 403 before any handler runs).
+//
+// It lives here, ahead of every mount, so a capability router added later cannot
+// silently ship without it.
+playerRouter.use(noindex, requireAuth)
+
+playerRouter.use('/account', accountRouter)
+playerRouter.use('/shard', shardRouter)
+playerRouter.use('/appeals', appealsRouter)
+
+module.exports = playerRouter