fix: resolve login network error behind Traefik proxy

app.py

@@ -16,11 +16,9 @@ def create_app():
     app.secret_key = SECRET_KEY
     app.config['SESSION_COOKIE_HTTPONLY'] = True
     app.config['SESSION_COOKIE_SAMESITE'] = 'Lax'
-    app.config['SESSION_COOKIE_SECURE'] = os.getenv('FLASK_ENV') == 'production'
     app.config['PERMANENT_SESSION_LIFETIME'] = 86400  # 24 hours
-    app.config['PREFERRED_URL_SCHEME'] = 'https'
     
-    # Trust the reverse proxy headers from Coolify/Traefik
+    # Behind Coolify/Traefik: trust proxy headers
     from werkzeug.middleware.proxy_fix import ProxyFix
     app.wsgi_app = ProxyFix(app.wsgi_app, x_for=1, x_proto=1, x_host=1, x_prefix=1)
     

docker-compose.yml

@@ -15,7 +15,6 @@ services:
       - SECRET_KEY=${SECRET_KEY:-}
       - TTS_API_URL=${TTS_API_URL:-http://localhost:5010/api/v1}
       - TTS_API_KEY=${TTS_API_KEY:-}
-      - FLASK_ENV=production
     volumes:
       - type: bind
         source: /opt/apps/Audiobook Maker Pro-v4

templates/login.html

@@ -260,7 +260,7 @@
             
             <div class="login-footer">
                 <i class="bi bi-shield-lock me-1"></i>
-                Audiobook Maker Pro v3.1
+                Audiobook Maker Pro v4
             </div>
         </div>
     </div>
@@ -295,18 +295,33 @@
             // Hide previous error
             errorDiv.classList.remove('visible');
             
+            // Client-side validation
+            if (!username || !password) {
+                errorText.textContent = 'Please enter username and password.';
+                errorDiv.classList.add('visible');
+                return;
+            }
+            
             // Show loading
             loginBtn.disabled = true;
             btnText.textContent = 'Signing in...';
             spinner.style.display = 'inline-block';
             
             try {
-                const response = await fetch('/api/auth/login', {
+                const response = await fetch(window.location.origin + '/api/auth/login', {
                     method: 'POST',
                     headers: { 'Content-Type': 'application/json' },
-                    body: JSON.stringify({ username, password })
+                    body: JSON.stringify({ username, password }),
+                    redirect: 'follow',
+                    credentials: 'same-origin'
                 });
                 
+                // Handle non-JSON responses (e.g., 500 server error pages)
+                const contentType = response.headers.get('content-type') || '';
+                if (!contentType.includes('application/json')) {
+                    throw new Error('Server returned status ' + response.status);
+                }
+                
                 const data = await response.json();
                 
                 if (data.error) {
@@ -326,7 +341,8 @@
                 window.location.href = '/';
                 
             } catch (error) {
-                errorText.textContent = 'Network error. Please try again.';
+                console.error('Login fetch error:', error);
+                errorText.textContent = 'Connection error. Please try again.';
                 errorDiv.classList.add('visible');
                 loginBtn.disabled = false;
                 btnText.textContent = 'Sign In';