fix: add EE repo mount for sandbox and remove agent key listener

Add ~/windmill-ee-private mount to sandbox extra_mounts (needed for
.git access) and remove ArrowLeft/ArrowRight agent-switching keydown
handler from CreateWorktreeDialog.

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

README_WORKMUX_DEV.md

@@ -183,6 +183,8 @@ When using sandbox mode, the container needs explicit mounts to access the EE re
 ```yaml
 sandbox:
   extra_mounts:
+    - host_path: ~/windmill-ee-private
+      writable: true
     - host_path: ~/windmill-ee-private__worktrees
       writable: true
 ```

dev-dashboard/frontend/src/lib/CreateWorktreeDialog.svelte

@@ -45,13 +45,6 @@
         ? (idx + 1) % PROFILES.length
         : (idx - 1 + PROFILES.length) % PROFILES.length;
       profile = PROFILES[next].value;
-    } else if (e.key === "ArrowLeft" || e.key === "ArrowRight") {
-      e.preventDefault();
-      const idx = AGENTS.findIndex((a) => a.value === agent);
-      const next = e.key === "ArrowRight"
-        ? (idx + 1) % AGENTS.length
-        : (idx - 1 + AGENTS.length) % AGENTS.length;
-      agent = AGENTS[next].value;
     }
   }