test(e2e): update suite for shipped features + gate Chromium-only perms

The running test container had been built from an older tree; rebuilding it to
pick up current app code surfaced several tests that predated shipped
security/UX features:

- file-upload-attacks / rate-limit: assert the magic-byte rejection wording and
  upload a real decodable JPEG (a zero-buffer is now rejected at the boundary).
- ddos: open SSE via the single-use /stream/ticket flow, not the dead ?token=.
- recover-page / join: the PIN field auto-submits on the 4th digit, so don't
  race an explicit submit click against the ensuing navigation.
- gestures-doubletap / sheet-escape: target the lightbox by aria-labelledby and
  anchor the radio accessible-name match at the start (gated dialog semantics).

playwright.config: camera/mic/clipboard are Chromium-only permissions (they threw
"Unknown permission: camera" on firefox/webkit and failed the test at context
creation); grant them per-Chromium-project. firefox-android drops the
unsupported isMobile flag.

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

e2e/page-objects/recover-page.ts

@@ -21,7 +21,15 @@ export class RecoverPage {
 
   async recover(name: string, pin: string) {
     await this.nameInput.fill(name);
+    // Filling the 4th digit fires the form's auto-submit ($effect on
+    // pin.length === 4, see pin-auto-submit.spec). An explicit submit click would
+    // race the ensuing navigation and detach mid-click, so only click as a
+    // fallback if the button is still around (e.g. a partial / failed PIN).
     await this.pinInput.fill(pin);
-    await this.submitButton.click();
+    if (await this.submitButton.isEnabled().catch(() => false)) {
+      await this.submitButton.click().catch(() => {
+        /* auto-submit already navigated — nothing to click */
+      });
+    }
   }
 }