fix(forge): quitter le plein ecran avant d'ouvrir l'assistant IA (BUG-056)

tests/frontend/forge-completion.test.mjs

@@ -221,6 +221,14 @@ test("Forge autosave keeps the buffer dirty if edits arrive during the request",
   assert.match(fn[1], /if \(val\(\) !== content\) \{ scheduleAutoSave\(\); return; \}/);
 });
 
+test("Forge leaves fullscreen before opening the shared assistant", () => {
+  const fn = FORGE_HTML.match(/function openAssistant\(\) \{([\s\S]*?)\n  \}/);
+  assert.ok(fn, "openAssistant not found");
+  assert.match(fn[1], /document\.fullscreenElement/);
+  assert.match(fn[1], /document\.exitFullscreen\(\)/);
+  assert.match(fn[1], /postMessage\(\{ type: 'forge-open-ai' \}, '\*'\)/);
+});
+
 // ── Summary ────────────────────────────────────────────────────────────────
 console.log(`\n${testCount} passed, ${failCount} failed`);
 process.exit(failCount > 0 ? 1 : 0);