Fix Google OAuth iframe 403 block

dashboard.py

@@ -674,7 +674,7 @@ if creds is None:
                 <span class="trust-badge">🛡️ 256-bit Encrypted</span>
                 <span class="trust-badge">🚫 No Data Stored</span>
             </div>
-            <a href="{auth_url}" target="_self" class="login-btn">
+            <a href="{auth_url}" target="_blank" class="login-btn">
                 ▶ &nbsp; Sign in with YouTube
             </a>
             <div class="login-trust-line">

youtube_auth.py

@@ -26,6 +26,9 @@ def get_client_config():
     raise FileNotFoundError("No Google credentials found.")
 
 def get_redirect_uri():
+    space_host = os.getenv("SPACE_HOST")
+    if space_host:
+        return f"https://{space_host}/"
     render_url = os.getenv("RENDER_EXTERNAL_URL")
     if render_url:
         return f"{render_url}/"