fix: Expose Oauth Client ID to static frontend

- Added `/api/config/oauth` GET endpoint to FastAPI to expose the Space's automatically injected `OAUTH_CLIENT_ID`.
- Modified `ClientApp.tsx` to fetch the Client ID before attempting OAuth redirect validation or login URL generation.
- Fixes "Missing clientId" errors thrown by `@huggingface/hub` caused by the static Next.js HTML being completely disconnected from the Docker container's environment variables.

api.py

@@ -149,6 +149,12 @@ def generate_image(req: ImageGenerationRequest):
     else:
         raise HTTPException(status_code=500, detail=status_msg or "Failed to generate image.")
 
+@app.get("/api/config/oauth")
+def get_oauth_config():
+    return {
+        "oauth_client_id": os.environ.get("OAUTH_CLIENT_ID")
+    }
+
 @app.post("/api/save_character")
 def save_character(req: PromptRequest):
     args = req.to_args()

frontend/src/components/ClientApp.tsx

@@ -45,7 +45,12 @@ export default function ClientApp() {
     // 1. Handle OAuth Redirect
     const handleOAuth = async () => {
         try {
-            const oauthResult = await oauthHandleRedirectIfPresent();
+            // First fetch the client ID provided by Hugging Face to our backend
+            const configRes = await fetch(`${API_URL}/api/config/oauth`);
+            const config = await configRes.json();
+            const clientId = config.oauth_client_id;
+            
+            const oauthResult = await oauthHandleRedirectIfPresent(clientId ? { clientId } : undefined);
             if (oauthResult) {
                 setHfToken(oauthResult.accessToken);
                 localStorage.setItem('hf_auth_token', oauthResult.accessToken);
@@ -53,7 +58,7 @@ export default function ClientApp() {
                 window.history.replaceState({}, document.title, window.location.pathname);
                 setStatusMsg("Successfully authenticated with Hugging Face!");
             }
-        } catch (e) {
+        } catch (e: any) {
             console.error("OAuth error", e);
         }
     };
@@ -263,7 +268,16 @@ export default function ClientApp() {
 
   const handleHFLogin = async () => {
     try {
+        const configRes = await fetch(`${API_URL}/api/config/oauth`);
+        const config = await configRes.json();
+        const clientId = config.oauth_client_id;
+        
+        if (!clientId) {
+            throw new Error("OAUTH_CLIENT_ID not found. Is your Space configured correctly with hf_oauth: true?");
+        }
+        
         const url = await oauthLoginUrl({
+            clientId: clientId,
             scopes: "openid profile inference-api"
         });
         window.location.href = url;