refactor(desktop): extract hidden Playwright CDP target helper

Move CDPTargetDescriptor and the reclaim predicate out of
playwright-cdp.ts into a dedicated module so the reclamation rule can be
unit-tested in isolation and reused without pulling in the whole hidden
browser manager.

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

apps/desktop-client/src/main/playwright-cdp-targets.ts

@@ -0,0 +1,29 @@
+export interface CDPTargetDescriptor {
+  id?: string;
+  type?: string;
+  title?: string;
+  url?: string;
+}
+
+const hiddenPlaywrightTargetMarkers = [
+  "hidden-playwright",
+  "geo-hidden-playwright-token",
+] as const;
+
+export function isReclaimableHiddenPlaywrightTarget(target: CDPTargetDescriptor): boolean {
+  if ((target.type ?? "").trim() !== "page") {
+    return false;
+  }
+  if (!(target.id ?? "").trim()) {
+    return false;
+  }
+
+  const title = target.title ?? "";
+  const url = target.url ?? "";
+  const haystack = `${title}\n${url}`.toLowerCase();
+
+  // Blank Electron page targets can belong to visible BrowserWindow shells.
+  // Only reclaim targets that we can prove were created by the hidden
+  // Playwright bootstrap flow.
+  return hiddenPlaywrightTargetMarkers.some((marker) => haystack.includes(marker));
+}