feat(shard): Protocol 2.0 boards UI — guilds, governors, houses, players-online

Phase 2: the public UI for the four new boards, following the ChampSpawns live
pattern (snapshot via useAsync + merge SSE deltas with useShardFeed).

- Players Online widget (components/PlayersOnline.jsx): total + region breakdown
  rolled up into display buckets (data/regionBuckets.js — the one place to retune
  the grouping); live via presence.online. Placed on the Shard page, replacing the
  static players-online stat tile.
- Guilds (/site/guilds): searchable board of rosters/alliances/leaders with a
  "recently joined" strip from guild.join.
- Governors (/site/governors): one card per city with a placeholder crest
  (data/cityCrests.js — swap for real art without touching components), election
  phase badge + autoPickAt countdown, and an on-demand "past governors" term
  history (the look-back reads the ledger captured in Phase 1). Clean empty state
  when City Loyalty isn't enabled.
- Houses (/site/houses): searchable registry with decay badges; price labelled
  "placement value", not a for-sale flag.
- API client methods + nav links (Guilds / Governors / Houses).

Client build clean (240 modules).

Refs .plans/protocol2-integration.md (Phase 2).

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>

client/src/App.jsx

@@ -19,6 +19,9 @@ import Status from './routes/public/Status.jsx'
 import Shard from './routes/public/Shard.jsx'
 import ShardActivity from './routes/public/ShardActivity.jsx'
 import ChampSpawns from './routes/public/ChampSpawns.jsx'
+import Guilds from './routes/public/Guilds.jsx'
+import Governors from './routes/public/Governors.jsx'
+import Houses from './routes/public/Houses.jsx'
 import Wiki from './routes/wiki/Wiki.jsx'
 import WikiArticle from './routes/wiki/WikiArticle.jsx'
 import CmsPage from './routes/public/CmsPage.jsx'
@@ -84,6 +87,9 @@ export default function App() {
             <Route path="/site/shard" element={<Shard />} />
             <Route path="/site/shard/activity" element={<ShardActivity />} />
             <Route path="/site/champs" element={<ChampSpawns />} />
+            <Route path="/site/guilds" element={<Guilds />} />
+            <Route path="/site/governors" element={<Governors />} />
+            <Route path="/site/houses" element={<Houses />} />
             <Route path="/wiki" element={<Wiki />} />
             <Route path="/wiki/:slug" element={<WikiArticle />} />
             {/* CMS pages: top-level /:slug, matched only after the named routes