Fix networkidle timeouts and Firefox cookie domain normalization

- Replace networkidle with domcontentloaded + 5s race in goto, click,
  and session_restore — SPAs with persistent connections (LinkedIn,
  Gmail) never reach networkidle
- Normalize .www. cookie domains in Firefox importer — Playwright
  silently drops cookies with .www.example.com domains

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

dist/browser.js

@@ -337,14 +337,17 @@ export class ClaudeBrowser {
     }
     async goto(url) {
         const page = this.ensurePage();
-        await page.goto(url, { waitUntil: 'networkidle' });
+        await page.goto(url, { waitUntil: 'domcontentloaded' });
+        // Best-effort wait for network to settle — SPAs with persistent connections
+        // (LinkedIn, Twitter, Gmail) never reach networkidle, so cap at 5s
+        await Promise.race([page.waitForLoadState('networkidle'), page.waitForTimeout(5000)]).catch(() => { });
         return { url: page.url(), title: await page.title() };
     }
     async click(selector) {
         const page = this.ensurePage();
         await this.previewAction(selector, 'CLICK');
         await page.click(selector);
-        await page.waitForLoadState('networkidle').catch(() => { });
+        await Promise.race([page.waitForLoadState('networkidle'), page.waitForTimeout(5000)]).catch(() => { });
         return { url: page.url() };
     }
     async type(selector, text) {