fix: inline git test feedback and use form URLs (0.20.1)

Show git check result next to the button, scroll into view, and test unsaved repo URLs from the form.

frontend/src/api.ts

@@ -581,9 +581,16 @@ export function saveAgentUpdateSettings(
   });
 }
 
-export function testAgentGitRelease(): Promise<AgentGitTestResult> {
+export interface AgentGitTestPayload {
+  rdp_git_repo_url?: string | null;
+  ssh_git_repo_url?: string | null;
+  git_branch?: string | null;
+}
+
+export function testAgentGitRelease(payload?: AgentGitTestPayload): Promise<AgentGitTestResult> {
   return apiFetch<AgentGitTestResult>("/api/v1/settings/agent-updates/test-git", {
     method: "POST",
+    body: JSON.stringify(payload ?? {}),
   });
 }