feat: Improve RegisterProjectDialog UX for long-running clone

- Add Loader2 spinner with "Cloning repository…" label while pending
- Keep Cancel button always enabled (no disabled gate)
- Map INTERNAL_SERVER_ERROR to user-friendly clone failure message
- Invalidate listProjects cache on success so new card appears immediately

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

apps/web/src/components/RegisterProjectDialog.tsx

@@ -10,6 +10,7 @@ import {
 import { Button } from "@/components/ui/button";
 import { Input } from "@/components/ui/input";
 import { Label } from "@/components/ui/label";
+import { Loader2 } from "lucide-react";
 import { toast } from "sonner";
 import { trpc } from "@/lib/trpc";
 
@@ -27,13 +28,20 @@ export function RegisterProjectDialog({
   const [defaultBranch, setDefaultBranch] = useState("main");
   const [error, setError] = useState<string | null>(null);
 
+  const utils = trpc.useUtils();
+
   const registerMutation = trpc.registerProject.useMutation({
     onSuccess: () => {
       onOpenChange(false);
       toast.success("Project registered");
+      void utils.listProjects.invalidate();
     },
     onError: (err) => {
-      setError(err.message);
+      if (err.data?.code === "INTERNAL_SERVER_ERROR") {
+        setError("Failed to clone repository. Check the URL and try again.");
+      } else {
+        setError(err.message);
+      }
     },
   });
 
@@ -109,7 +117,14 @@ export function RegisterProjectDialog({
               Cancel
             </Button>
             <Button type="submit" disabled={!canSubmit}>
-              {registerMutation.isPending ? "Registering..." : "Register"}
+              {registerMutation.isPending ? (
+                <>
+                  <Loader2 className="animate-spin mr-2 h-4 w-4" />
+                  Cloning repository…
+                </>
+              ) : (
+                "Register"
+              )}
             </Button>
           </DialogFooter>
         </form>