feat(proxy): add full URL mode and refactor endpoint rewriting

- Add `isFullUrl` provider meta to treat base_url as complete API endpoint
- Remove hardcoded `?beta=true` from Claude adapter, pass through from client
- Refactor forwarder endpoint rewriting with proper query string handling
- Block provider switching when proxy is required but not running
- Add full URL toggle UI in endpoint field with i18n (zh/en/ja)

tests/hooks/useProviderActions.test.tsx

@@ -7,11 +7,15 @@ import type { Provider, UsageScript } from "@/types";
 
 const toastSuccessMock = vi.fn();
 const toastErrorMock = vi.fn();
+const toastInfoMock = vi.fn();
+const toastWarningMock = vi.fn();
 
 vi.mock("sonner", () => ({
   toast: {
     success: (...args: unknown[]) => toastSuccessMock(...args),
     error: (...args: unknown[]) => toastErrorMock(...args),
+    info: (...args: unknown[]) => toastInfoMock(...args),
+    warning: (...args: unknown[]) => toastWarningMock(...args),
   },
 }));
 
@@ -116,6 +120,8 @@ beforeEach(() => {
   openclawApiSetDefaultModelMock.mockReset();
   toastSuccessMock.mockReset();
   toastErrorMock.mockReset();
+  toastInfoMock.mockReset();
+  toastWarningMock.mockReset();
 
   addProviderMutation.isPending = false;
   updateProviderMutation.isPending = false;
@@ -185,6 +191,28 @@ describe("useProviderActions", () => {
     expect(settingsApiApplyMock).not.toHaveBeenCalled();
   });
 
+  it("blocks switching providers that require proxy when proxy is not running", async () => {
+    const { wrapper } = createWrapper();
+    const provider = createProvider({
+      category: "custom",
+      meta: {
+        apiFormat: "openai_chat",
+      },
+    });
+
+    const { result } = renderHook(() => useProviderActions("claude", false), {
+      wrapper,
+    });
+
+    await act(async () => {
+      await result.current.switchProvider(provider);
+    });
+
+    expect(switchProviderMutateAsync).not.toHaveBeenCalled();
+    expect(toastWarningMock).toHaveBeenCalledTimes(1);
+    expect(settingsApiGetMock).not.toHaveBeenCalled();
+  });
+
   it("should sync plugin config when switching Claude provider with integration enabled", async () => {
     switchProviderMutateAsync.mockResolvedValueOnce(undefined);
     settingsApiGetMock.mockResolvedValueOnce({