UI overhaul "Living Codex" C+D: Lucide icons + left-rail shell

- Replace the top nav with a left rail + top context bar ("GM mission control"):
  gilt crown wordmark, nav grouped At the Table / Reference with Lucide icons and a
  gold active state (accent-glow + gilt left edge), a collapse toggle
  (uiStore.railCollapsed). A single responsive rail = icon strip (68px) on phones /
  when collapsed, full labels on >= sm.
- Top bar: campaign switcher, a ⌘K search pill, and every existing control preserved
  (PlayerSessionBadge, Session panel toggle, HandoutControl, SessionControl host,
  theme toggle as Sun/Moon, Settings) — same aria-labels/testids so e2e is intact.
- bun add lucide-react. Rail is print:hidden (sheets export clean).

223 unit + 34 e2e + 2 realtime green; nav contract (aria-label="Primary", link names) preserved.

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>

bun.lock

@@ -15,6 +15,7 @@
         "dexie-react-hooks": "^1.1.7",
         "dompurify": "^3.2.3",
         "fuse.js": "^7.0.0",
+        "lucide-react": "^1.17.0",
         "nanoid": "^5.0.9",
         "react": "^19.0.0",
         "react-dom": "^19.0.0",
@@ -1026,6 +1027,8 @@
 
     "lru-cache": ["lru-cache@11.5.1", "", {}, "sha512-RPimw/7aMdv2oqRrxKwvZXcPfwBrn/JZ2xYcY9Hus/6LaS3VOAKVWKWgNLCFSiOm1ESXinjsDlidVU7JlnCN2A=="],
 
+    "lucide-react": ["lucide-react@1.17.0", "", { "peerDependencies": { "react": "^16.5.1 || ^17.0.0 || ^18.0.0 || ^19.0.0" } }, "sha512-9FA9evdox/JQL5PT57fdA1x/yg8T7knJ98+zjTL3UfKza6pflQUUh3XtaQIHKvnsJw1lmsEyHVlt5jchYxOQ5w=="],
+
     "lz-string": ["lz-string@1.5.0", "", { "bin": { "lz-string": "bin/bin.js" } }, "sha512-h5bgJWpxJNswbU7qCrV0tIKQCaS3blPDrqKWx+QxzuzL1zGUzij9XCWLrSLsJPu5t+eWA/ycetzYAO5IOMcWAQ=="],
 
     "magic-string": ["magic-string@0.30.21", "", { "dependencies": { "@jridgewell/sourcemap-codec": "^1.5.5" } }, "sha512-vd2F4YUyEXKGcLHoq+TEyCjxueSeHnFxyyjNp80yg0XV4vUhnDer/lvvlqM/arB5bXQN5K2/3oinyCRyx8T2CQ=="],