Corrige ReferenceError safeExtractError e adiciona retries resilientes multi-engine no gerador de imagens

public/app.js

@@ -11,6 +11,26 @@ function escapeHtml(text) {
     .replace(/'/g, "'");
 }
 
+// Helper global para extração segura de erros de resposta HTTP no frontend
+async function safeExtractError(resp, defaultMsg = 'Erro na operação') {
+  if (!resp) return defaultMsg;
+  try {
+    const text = await resp.text();
+    try {
+      const json = JSON.parse(text);
+      return json.error || defaultMsg;
+    } catch (e) {
+      if (resp.status === 502 || text.includes('Bad Gateway')) {
+        return 'O servidor está temporariamente ocupado processando a requisição. Por favor, tente novamente em instantes.';
+      }
+      return text.slice(0, 160) || defaultMsg;
+    }
+  } catch (e) {
+    return defaultMsg;
+  }
+}
+
+
 // Função global para exibir notificações elegantes estilo Toast
 function showToast(message, type = 'info') {
   let container = document.getElementById('toast-container');

server.js

@@ -586,30 +586,44 @@ app.post('/api/comics/generate-frame', requireAuth, async (req, res) => {
     console.warn('[Comics Image] Falha/Timeout no MiniMax image-01 (' + minimaxErr.message + '), acionando gerador fallback...');
   }
 
-  // Tentativa 2 (Fallback): Pollinations FLUX de alta resolução estilizado 3D Pixar
+  // Tentativa 2 (Fallback Resiliente Multi-Engine com Retries):
   if (!imageBuffer) {
-    providerUsed = 'pollinations-flux';
-    try {
-      const is169 = proporcao === '16:9' || prompt.includes('16:9');
-      const width = is169 ? 1280 : 1024;
-      const height = is169 ? 720 : 768;
-      const enhancedPrompt = encodeURIComponent(`${prompt}, 3d pixar disney style, digital children book illustration, vibrant colors, masterpiece, cinematic lighting`);
-      const fallbackUrl = `https://image.pollinations.ai/prompt/${enhancedPrompt}?width=${width}&height=${height}&nologo=true&seed=${Math.floor(Math.random() * 100000)}`;
+    const is169 = proporcao === '16:9' || (prompt && prompt.includes('16:9'));
+    const width = is169 ? 1280 : 1024;
+    const height = is169 ? 720 : 768;
+    const cleanPrompt = (prompt || 'cute children book illustration').replace(/[^\w\s,.-]/gi, '');
+    const enhancedPrompt = encodeURIComponent(`${cleanPrompt}, 3d pixar disney style, digital children book illustration, vibrant colors, masterpiece, cinematic lighting`);
+    
+    const engines = ['flux', 'turbo'];
 
-      const controller = new AbortController();
-      const timeoutId = setTimeout(() => controller.abort(), 30000);
+    for (const engine of engines) {
+      if (imageBuffer) break;
+      for (let attempt = 1; attempt <= 2; attempt++) {
+        try {
+          providerUsed = `pollinations-${engine}`;
+          const seed = Math.floor(Math.random() * 1000000);
+          const fallbackUrl = `https://image.pollinations.ai/prompt/${enhancedPrompt}?width=${width}&height=${height}&model=${engine}&nologo=true&seed=${seed}`;
 
-      const fbResp = await fetch(fallbackUrl, { signal: controller.signal });
-      clearTimeout(timeoutId);
+          const controller = new AbortController();
+          const timeoutId = setTimeout(() => controller.abort(), 25000);
 
-      if (fbResp.ok) {
-        imageBuffer = Buffer.from(await fbResp.arrayBuffer());
-        console.log('[Comics Image] Imagem gerada com sucesso via Fallback Inteligente (Pollinations Flux).');
-      } else {
-        throw new Error(`Fallback HTTP ${fbResp.status}`);
+          const fbResp = await fetch(fallbackUrl, { signal: controller.signal });
+          clearTimeout(timeoutId);
+
+          if (fbResp.ok) {
+            imageBuffer = Buffer.from(await fbResp.arrayBuffer());
+            console.log(`[Comics Image] Imagem gerada com sucesso via Fallback (${providerUsed}, tentativa ${attempt}).`);
+            break;
+          } else {
+            console.warn(`[Comics Image] Fallback ${providerUsed} tentativa ${attempt} respondeu ${fbResp.status}`);
+            if (fbResp.status === 429) {
+              await new Promise(r => setTimeout(r, 700 * attempt));
+            }
+          }
+        } catch (fbErr) {
+          console.warn(`[Comics Image] Erro no fallback ${engine} tentativa ${attempt}:`, fbErr.message);
+        }
       }
-    } catch (fbErr) {
-      console.error('[Comics Image] Erro também no provedor Fallback:', fbErr.message);
     }
   }