[iamnbutler]

Open folder and Clone from URL now say when they change what you typed or drop it. They also clear errors once you change a field, and long paths stay inside the dialog (^302, ^304, ^314, ^325, ^326, ^808).

• Open folder inside a repository. Ace still opens the enclosing repository, and now says so: a toast reads "Opened r — …/r/sub is inside the Git repository at …/r, so Ace opened that." The host's project-open names the folder you asked for in a new from field. This applies to the native panel too, since both go through open.
• A second checkout of a project. Opening one toasts "Hello-World is already a project at …/c1/Hello-World — Channels in it keep starting from that checkout."
• Clone from URL now:
  • says why gitlab.com/foo/bar can't clone. It uses the host's own message, which is now shared as NOT_GITHUB.
  • says "octocat/Hello-World is already a project at …. Another copy won't add a second project." before cloning a second copy.
  • clears errors when the URL, the folder or the chosen folder changes.
  • wraps long paths. The form and footer no longer widen the dialog's grid, so Cancel stays in view.
• Open a folder clears its error when the path changes, and wraps long ones.
• Initialize Git card. The card reads its folder again when it's shown and when the window regains focus, so a commit made in a terminal clears it without a reload.

Smoke-tested on an isolated loopback host (own ACE_HOME, config, keychain service, port 4955) in headless Chromium, with real Git and a real clone of octocat/Hello-World:

1. r/sub inside an uncommitted repo showed the "Opened r" toast and the Initialize Git card. After git commit in a shell and a window focus, the card was gone.
2. Opening a file showed the error, which cleared as the path changed.
3. gitlab.com/foo/bar showed the GitHub message.
4. Cloning into a non-empty folder showed the error inside the dialog at 1200 px and 390 px, with Cancel in view, and it cleared when the folder changed.
5. A clone to c1 worked. The second Clone dialog said it's already a project at c1/Hello-World, and opening c2/Hello-World toasted the same.

Not covered here: the card's wording for a folder that has .git but no commits (^311).

Part of #615.

Built in Ace

No. This was made from Claude Code as a fix-train worker, using a headless Chromium to drive an isolated source host. Ace has no way yet to run an agent-driven fix queue across several workers like this (#5).