diff --git a/src/components/wizard/RemoteConfigStep.test.tsx b/src/components/wizard/RemoteConfigStep.test.tsx
index 2d6cdad..2677158 100644
--- a/src/components/wizard/RemoteConfigStep.test.tsx
+++ b/src/components/wizard/RemoteConfigStep.test.tsx
@@ -119,4 +119,112 @@ describe('RemoteConfigStep', () => {
       });
     });
   });
+
+  describe('BACK-01 (Phase 6): OneDrive form', () => {
+    it('renders OAuth Token field', async () => {
+      renderWithBackend('onedrive' as BackendType);
+      await waitFor(() => {
+        expect(screen.getByLabelText(/oauth token/i)).toBeDefined();
+      });
+    });
+    it('renders Drive ID field', async () => {
+      renderWithBackend('onedrive' as BackendType);
+      await waitFor(() => {
+        expect(screen.getByLabelText(/drive id/i)).toBeDefined();
+      });
+    });
+    it('renders Drive Type select', async () => {
+      renderWithBackend('onedrive' as BackendType);
+      await waitFor(() => {
+        expect(screen.getByLabelText(/drive type/i)).toBeDefined();
+      });
+    });
+  });
+
+  describe('BACK-02 (Phase 6): SFTP form', () => {
+    it('renders Host field', async () => {
+      renderWithBackend('sftp' as BackendType);
+      await waitFor(() => {
+        expect(screen.getByLabelText(/host/i)).toBeDefined();
+      });
+    });
+    it('renders Username field', async () => {
+      renderWithBackend('sftp' as BackendType);
+      await waitFor(() => {
+        expect(screen.getByLabelText(/username/i)).toBeDefined();
+      });
+    });
+    it('shows Password tab button by default', async () => {
+      renderWithBackend('sftp' as BackendType);
+      await waitFor(() => {
+        expect(screen.getByText(/^password$/i, { selector: 'button' })).toBeDefined();
+      });
+    });
+    it('shows Private Key tab button', async () => {
+      renderWithBackend('sftp' as BackendType);
+      await waitFor(() => {
+        expect(screen.getByText(/private key/i, { selector: 'button' })).toBeDefined();
+      });
+    });
+    it('switching to Private Key tab CSS-hides password field and shows key_pem field', async () => {
+      renderWithBackend('sftp' as BackendType);
+      await waitFor(() => {
+        expect(screen.getByText(/private key/i, { selector: 'button' })).toBeDefined();
+      });
+      fireEvent.click(screen.getByText(/private key/i, { selector: 'button' }));
+      await waitFor(() => {
+        const passInput = screen.getByLabelText(/^password$/i);
+        const passWrapper = passInput.closest('div.hidden');
+        expect(passWrapper).toBeDefined();
+        const keyInput = screen.getByLabelText(/private key.*pem/i);
+        const keyWrapper = keyInput.closest('div.block');
+        expect(keyWrapper).toBeDefined();
+      });
+    });
+    it('switching SFTP auth tabs preserves hidden field value', async () => {
+      const user = userEvent.setup();
+      renderWithBackend('sftp' as BackendType);
+      await waitFor(() => {
+        expect(screen.getByLabelText(/^password$/i)).toBeDefined();
+      });
+      await user.type(screen.getByLabelText(/^password$/i), 'mysftppass');
+      fireEvent.click(screen.getByText(/private key/i, { selector: 'button' }));
+      fireEvent.click(screen.getByText(/^password$/i, { selector: 'button' }));
+      await waitFor(() => {
+        const input = screen.getByLabelText(/^password$/i) as HTMLInputElement;
+        expect(input.value).toBe('mysftppass');
+      });
+    });
+  });
+
+  describe('BACK-03 (Phase 6): Google Cloud Storage form', () => {
+    it('renders Project Number field', async () => {
+      renderWithBackend('gcs' as BackendType);
+      await waitFor(() => {
+        expect(screen.getByLabelText(/project number/i)).toBeDefined();
+      });
+    });
+    it('renders Service Account JSON field', async () => {
+      renderWithBackend('gcs' as BackendType);
+      await waitFor(() => {
+        expect(screen.getByLabelText(/service account json/i)).toBeDefined();
+      });
+    });
+  });
+
+  describe('BACK-04 (Phase 6): Backblaze B2 form', () => {
+    it('renders Application Key ID field', async () => {
+      renderWithBackend('b2' as BackendType);
+      await waitFor(() => {
+        expect(screen.getByLabelText(/application key id/i)).toBeDefined();
+      });
+    });
+    it('renders Application Key field', async () => {
+      renderWithBackend('b2' as BackendType);
+      await waitFor(() => {
+        // Matches "Application Key" but not "Application Key ID"
+        expect(screen.getByLabelText(/application key$/i)).toBeDefined();
+      });
+    });
+  });
 });