fix(web): open articles as a card, drop search, unstick stale app shell

- Service worker activates new versions immediately (skipWaiting +
  clientsClaim). In prompt mode a waiting worker kept serving the previous
  build to tabs that never send SKIP_WAITING, so the old UI hit the new API
  and showed "Aucun contenu disponible" on every article. Pages already
  controlled get a reload toast; lazy chunks missing after a deploy reload
  once.
- Reader opens as a large card above the dimmed grid: close with ✕, Escape
  or a click beside it; previous/next arrows on the sides (desktop) and a
  bottom bar with the next title (all sizes).
- Remove search, the focus banner and decorative headers; plain sentence-
  case labels instead of tracked capitals; quieter dashboard header.
- Fix horizontal overflow of cards and reader navigation on phones.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

web/vite.config.ts

@@ -35,6 +35,12 @@ export default defineConfig({
         globPatterns: ['**/*.{js,css,html,svg}', '**/*-latin-wght-*.woff2', '**/*-latin-[47]00-*.woff2'],
         navigateFallbackDenylist: [/^\/api\//, /^\/health/],
         cleanupOutdatedCaches: true,
+        // Activate new versions immediately. A waiting worker would keep
+        // serving a stale app shell to clients that never send SKIP_WAITING
+        // (e.g. tabs still running a previous build), so the old UI would talk
+        // to the new API. The app shows a reload toast instead of reloading.
+        skipWaiting: true,
+        clientsClaim: true,
         runtimeCaching: [
           {
             // Opened articles stay readable offline.