fix(web): support cloning existing repositories

- Make the add repository dialog explicitly support cloning from a remote git server
- Keep blank repo creation as a fallback option
- Add validation and tests for the clone-first flow

Quality gates: tsc --noEmit, vitest run src/components/repositories-settings-tab.test.tsx

apps/web/src/components/repositories-settings-tab.test.tsx

@@ -32,7 +32,7 @@ afterEach(() => {
 });
 
 describe("RepositoriesSettingsTab", () => {
-  it("opens create dialog and submits a repository", async () => {
+  it("opens create dialog and clones an existing repository", async () => {
     const listMock = vi.spyOn(gitRepositoriesApi, "listRepositories").mockResolvedValue(mockRepositories);
     const createMock = vi.spyOn(gitRepositoriesApi, "createRepository").mockResolvedValue(mockRepositories[0]);
 
@@ -46,14 +46,34 @@ describe("RepositoriesSettingsTab", () => {
     fireEvent.change(screen.getByPlaceholderText(/repository-name/i), {
       target: { value: "New Repo" },
     });
-    fireEvent.click(screen.getByRole("button", { name: /create/i }));
+    fireEvent.change(screen.getByPlaceholderText(/github.com\/user\/repo.git/i), {
+      target: { value: "https://github.com/user/repo.git" },
+    });
+    fireEvent.click(screen.getByRole("button", { name: /clone repository/i }));
 
     await waitFor(() => {
       expect(createMock).toHaveBeenCalledWith("proj-1", {
         name: "New Repo",
-        remote_url: undefined,
+        remote_url: "https://github.com/user/repo.git",
       });
     });
     expect(listMock).toHaveBeenCalledTimes(2);
   });
+
+  it("shows validation when cloning without a remote url", async () => {
+    vi.spyOn(gitRepositoriesApi, "listRepositories").mockResolvedValue(mockRepositories);
+    render(<RepositoriesSettingsTab />);
+
+    await waitFor(() => {
+      expect(screen.getByText("Main Repo")).toBeInTheDocument();
+    });
+
+    fireEvent.click(screen.getByRole("button", { name: /add repository/i }));
+    fireEvent.change(screen.getByPlaceholderText(/repository-name/i), {
+      target: { value: "New Repo" },
+    });
+    fireEvent.click(screen.getByRole("button", { name: /clone repository/i }));
+
+    expect(screen.getByText(/remote url is required/i)).toBeInTheDocument();
+  });
 });