Open a thread from outside the app with t3code://thread/<environmentId>/<threadId>

[jamesvillarrubia]

The desktop app registers the t3code URL scheme, but nothing handles a t3code:// link that arrives from outside. open "t3code://thread/<env>/<thread>" brings T3 Code to the front and stays on the current thread.

I run a local work picker in the Browser panel that lists stories and the T3 threads working on them. Its "open" button needs to switch the main window to a specific thread. The panel loads links inside its own tab, so the only route to the main window is an OS-level URL.

A patch is up as #14286 (12 files, +397/-14).

• packages/shared/src/threadDeepLink.ts parses t3code://thread/<env>/<thread> (and t3code-dev://). It accepts ids matching [A-Za-z0-9_-]{1,128} and rejects everything else: other hosts, extra segments, encoded slashes, credentials, and ports.
• The main process listens for open-url and second-instance and sends the link through the existing dispatchMenuAction channel. No new IPC channel, preload change, or contract change.
• __root.tsx navigates to /$environmentId/$threadId.
• ElectronProtocol.ts already 404s any host other than app, so the thread host never collides with app assets.

Would you take this? If you want a different shape, I can trim the PR to it.

[juliusmarminge]

Duplicate of #6834 (Ideas — same ask: handle t3code:// from outside so the desktop main window navigates to a specific thread via open-url / second-instance).

That thread is still open. Prior implementation #6008 was closed unmerged; your patch #14286 covers the same gap (path shape differs slightly: #6834/mobile use t3code://threads/…, the PR uses t3code://thread/… — please continue on #6834).

Near-misses left alone: #6816 (checkout-pr), #12587 (pairing deep link).