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/src/lib/lazy.ts

@@ -0,0 +1,23 @@
+import { lazy, type ComponentType } from 'react';
+
+/**
+ * React.lazy for a named export. After a deploy, chunks of the previous build
+ * no longer exist on the server: reload once to pick up the new version
+ * instead of showing a blank screen.
+ */
+// eslint-disable-next-line @typescript-eslint/no-explicit-any
+export function lazyNamed<T extends ComponentType<any>>(load: () => Promise<Record<string, unknown>>, name: string) {
+    return lazy(async () => {
+        try {
+            const mod = await load();
+            sessionStorage.removeItem('chunk-reload');
+            return { default: mod[name] as T };
+        } catch (err) {
+            if (!sessionStorage.getItem('chunk-reload')) {
+                sessionStorage.setItem('chunk-reload', '1');
+                window.location.reload();
+            }
+            throw err;
+        }
+    });
+}