fix: Settings page API endpoints and data handling

- Fixed handleSave to use separate /gmail and /telegram endpoints
- Changed /test-mail to /test-gmail endpoint
- Added proper null checks in loadSettings to prevent uncontrolled input warnings
- Settings now properly saved to backend with correct endpoint structure

frontend/src/pages/Settings.jsx

@@ -35,7 +35,13 @@ function Settings() {
       const response = await axios.get(`${API_URL}/api/settings`, {
         withCredentials: true,
       });
-      setSettings(response.data.data);
+      const data = response.data.data || {};
+      setSettings({
+        gmail_user: data.gmail_user || '',
+        gmail_app_password: data.gmail_app_password || '',
+        telegram_bot_token: data.telegram_bot_token || '',
+        telegram_chat_id: data.telegram_chat_id || '',
+      });
     } catch (error) {
       console.error('Failed to load settings:', error);
     } finally {
@@ -45,9 +51,16 @@ function Settings() {
 
   const handleSave = async () => {
     try {
-      await axios.put(`${API_URL}/api/settings`, settings, {
-        withCredentials: true,
-      });
+      await Promise.all([
+        axios.put(`${API_URL}/api/settings/gmail`, {
+          gmail_user: settings.gmail_user,
+          gmail_app_password: settings.gmail_app_password,
+        }, { withCredentials: true }),
+        axios.put(`${API_URL}/api/settings/telegram`, {
+          telegram_bot_token: settings.telegram_bot_token,
+          telegram_chat_id: settings.telegram_chat_id,
+        }, { withCredentials: true }),
+      ]);
       alert('Ayarlar kaydedildi!');
     } catch (error) {
       console.error('Failed to save settings:', error);
@@ -59,7 +72,7 @@ function Settings() {
     setTestLoading({ ...testLoading, mail: true });
     try {
       const response = await axios.post(
-        `${API_URL}/api/settings/test-mail`,
+        `${API_URL}/api/settings/test-gmail`,
         {},
         { withCredentials: true }
       );