Add browser pane element picker (#670)

* feat: add browser pane element picker

Port the browser pane from PR #198 and route picked elements through workspace attachments so the context follows every agent composer in a workspace.

Co-authored-by: Jason Kneen <jason.kneen@bouncingfish.com>

* docs: document electron platform overlays

* fix: harden browser pane navigation

* fix: polish browser tab interactions

* fix: route browser pane focus shortcuts

---------

Co-authored-by: Jason Kneen <jason.kneen@bouncingfish.com>

packages/app/src/screens/workspace/workspace-draft-agent-tab.tsx

@@ -342,6 +342,9 @@ export function WorkspaceDraftAgentTab({
   const setExplorerTabForCheckout = usePanelStore((state) => state.setExplorerTabForCheckout);
   const handleOpenWorkspaceAttachment = useCallback(
     (attachment: WorkspaceComposerAttachment) => {
+      if (attachment.kind !== "review") {
+        return;
+      }
       const checkout = {
         serverId,
         cwd: attachment.attachment.cwd,