put the previewed browser tab in the url

Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>

docs/workspace-panel-todo.md

@@ -667,7 +667,18 @@ All the same bug: an app guessing "am I being closed?" from an unmount, or payin
       walk the sweep instead of leaving the mailbox. `EMAIL_FOLDER` stays a global for now: it is read in
       one component and is view state rather than selection. Putting it in `?folder=` is a real but
       separate item.
-      Remaining here: Music, Browser. **Chat detail (`chat:selected-session`) is chat-owned —
+      **Browser is done** — `/browser/:tabId`, `BROWSER_SELECTED_TAB` deleted from its three readers.
+      The audit had this one filed under "probably leave as selection", on the grounds that a CDP target
+      id dies with the browser session so a durable URL is dubious. That is an argument about
+      *bookmarking*, and bookmarking is the least of what the URL was buying: the id lived in an onClick
+      closure, three components shared a global, and a tab row could not be cmd-clicked. The staleness
+      the audit worried about is real and is now handled where it shows — the preview tells "no tab open"
+      from "that tab is no longer attached" by checking the polled target list, which both panels read
+      from one React Query key, so it costs no extra request. Two defects fell out on the way: the row's
+      Focus and Close buttons were nested inside the row `<button>` (invalid HTML, held together by two
+      `stopPropagation` calls — they are siblings of the anchor now), and "Set up in Integrations" was a
+      raw `<a href>` that reloaded the whole SPA.
+      Remaining here: Music. **Chat detail (`chat:selected-session`) is chat-owned —
       leave it; it is written up in `COMMS/`.**
 
 ### 5.9 The context has grown an app-config section — _(found 2026-08-07)_