feat: controlBrowser 'search' action + one-sentence voice replies

- Add a one-shot `search` action (site=naver/google/daum/youtube/bing) that
  navigates the on-screen browser straight to the results page, so a small
  model can satisfy "search X on Naver" in a single tool call instead of a
  fragile navigate->type->enter chain.
- Sharpen the tool description to steer the router to controlBrowser (not
  webSearch) for anything that should happen IN the visible browser.
- System prompt: answer in one short sentence (voice assistant) — also cuts
  TTS time.

Co-Authored-By: Claude Opus 4.7 <noreply@anthropic.com>

bot/scripts/stream-test/chrome-control.mjs

@@ -97,6 +97,32 @@ try {
       break;
     }
 
+    case 'search': {
+      // One-shot "search on a site": build the engine's results URL so a small
+      // model doesn't have to chain navigate->type->enter. Visible on screen.
+      const q = String(cmd.query || '').trim();
+      if (!q) throw new Error('search: no query');
+      const site = String(cmd.site || 'google').toLowerCase();
+      const engines = {
+        naver: 'https://search.naver.com/search.naver?query=',
+        google: 'https://www.google.com/search?q=',
+        daum: 'https://search.daum.net/search?q=',
+        youtube: 'https://www.youtube.com/results?search_query=',
+        bing: 'https://www.bing.com/search?q=',
+      };
+      const base = engines[site] || engines.google;
+      const target = base + encodeURIComponent(q);
+      await front(page);
+      if (HAS_XDOTOOL && cmd.human !== false) {
+        try { await human.navigateOmnibox(target); await page.waitForLoadState('domcontentloaded').catch(() => {}); }
+        catch { await page.goto(target, { waitUntil: 'domcontentloaded' }); }
+      } else {
+        await page.goto(target, { waitUntil: 'domcontentloaded' });
+      }
+      out({ ok: true, site: engines[site] ? site : 'google', query: q, url: page.url(), title: await page.title().catch(() => '') });
+      break;
+    }
+
     case 'back': await front(page); await page.goBack({ waitUntil: 'domcontentloaded' }).catch(() => {}); out({ ok: true, url: page.url() }); break;
     case 'forward': await front(page); await page.goForward({ waitUntil: 'domcontentloaded' }).catch(() => {}); out({ ok: true, url: page.url() }); break;
     case 'refresh': await front(page); await reload(); out({ ok: true, url: page.url() }); break;