Stage 2: application shell (4 destinations, router, layout, a11y)

- Vite 6 build with hashed immutable assets (assets/index-[hash].js 2.63kB gz, style 1.18kB gz; index.html 0.92kB) — single-bundle, offline-safe shell (index.html no-cache, assets immutable) per ARCH §24
- index.html + manifest.webmanifest (standalone, / scope) + fallback.html Ring-0
- src/app/main.ts boot + layout + status placeholder (no IDB/Cache/SW/sync per Stage 2 SCOPE)
- src/app/layout.ts: banner, skip-link, main#main-content, bottom nav Emergency·Schedule·Map·Festival (Emergency first, --emergency accent #b91c1c/#ef4444, 64px nav, 48px targets)
- src/ui/router/router.ts: history-API, offline-safe deep links (/emergency canonical), normalizePath, routeForPath, no network
- 4 placeholder views (emergency/schedule/map/festival) + not-found, semantic h1/section/aria-labelledby, view-placeholder structural only (no real data)
- src/app/styles.css: phone-first, high-contrast, dark via prefers-color-scheme, large touch targets, one-handed, outdoor, reduced-motion guard
- Tests: tests/unit/shell.test.ts (14 tests: boot, landmarks, 4 destinations, emergency one-tap from every route, unknown routes, normalize, a11y) — jsdom; updated boundaries test for Stage 2 shell
- Lint: allowDefaultProject for vite.config.ts; boundaries B-1..B-7 enforced (eslint-plugin-boundaries), B-7 innerHTML guard
- CI passes: typecheck + lint + format + test (18 tests) + build
- No IDB/Cache/SW/DataPackage/sync/mesh/accounts per contract — directories remain .gitkeep

public/fallback.html

@@ -0,0 +1,33 @@
+<!doctype html>
+<html lang="en">
+  <head>
+    <meta charset="utf-8" />
+    <meta name="viewport" content="width=device-width, initial-scale=1" />
+    <title>Lumen — offline</title>
+    <meta name="color-scheme" content="light dark" />
+    <style>
+      body {
+        font-family: system-ui, sans-serif;
+        max-width: 40rem;
+        margin: 2rem auto;
+        padding: 0 1rem;
+        line-height: 1.5;
+      }
+      h1 {
+        font-size: 1.5rem;
+      }
+      .note {
+        border: 2px solid currentColor;
+        padding: 1rem;
+      }
+    </style>
+  </head>
+  <body>
+    <h1>Lumen</h1>
+    <p class="note" role="alert">
+      You are offline and the app shell is not cached. Emergency information is available from
+      festival staff and printed materials.
+    </p>
+    <p>When you are back online, open <a href="/">Lumen</a> to reload the app shell.</p>
+  </body>
+</html>