fix(journaling): optimize serper video search queries to prevent MDX hallucination

packages/thumbnail-generator/src/generator.ts

@@ -6,6 +6,12 @@ export interface ThumbnailGeneratorConfig {
   replicateApiKey: string;
 }
 
+export interface ThumbnailGenerateOptions {
+  model?: string;
+  systemPrompt?: string;
+  imagePrompt?: string; // Path to local reference image
+}
+
 export class ThumbnailGenerator {
   private replicate: Replicate;
 
@@ -18,21 +24,43 @@ export class ThumbnailGenerator {
   public async generateImage(
     topic: string,
     outputPath: string,
+    options?: ThumbnailGenerateOptions,
   ): Promise<string> {
-    const systemPrompt = `Technical blueprint / architectural illustration — clean lines, monochrome base with one highlighter accent color (yellow, pink, or green). Abstract, geometric, or diagrammatic illustrations only. 'Engineering notebook sketch' — precise, minimal, professional. No text in images. No people or realistic photos.`;
+    const defaultSystemPrompt = `A highly polished, ultra-minimalist conceptual illustration. Style: high-end tech agency, clean modern 3D or flat vector art, extensive use of negative space, elegant monochrome palette (whites, light grays) with a single vibrant accent color (neon green or electric blue). Extremely clean and precise geometry. Absolutely no text, no photorealism, no chaotic lines, no messy sketches, no people.`;
 
+    const systemPrompt = options?.systemPrompt || defaultSystemPrompt;
     const prompt = `${systemPrompt}\n\nTopic to illustrate abstractly: ${topic}`;
 
     console.log(`🎨 Generating thumbnail for topic: "${topic}"...`);
 
-    const output = await this.replicate.run("black-forest-labs/flux-1.1-pro", {
-      input: {
-        prompt,
-        aspect_ratio: "16:9",
-        output_format: "png",
-        output_quality: 90,
-        prompt_upsampling: false,
-      },
+    let inputPayload: any = {
+      prompt,
+      aspect_ratio: "16:9",
+      output_format: "png",
+      output_quality: 90,
+      prompt_upsampling: false,
+    };
+
+    if (options?.imagePrompt) {
+      console.log(`🖼️ Using image style reference: ${options.imagePrompt}`);
+      try {
+        const absImgPath = path.isAbsolute(options.imagePrompt)
+          ? options.imagePrompt
+          : path.resolve(process.cwd(), options.imagePrompt);
+        const imgBuffer = await fs.readFile(absImgPath);
+        const base64 = imgBuffer.toString("base64");
+        // Replicate models usually expect a data URI for image_prompt
+        inputPayload.image_prompt = `data:image/png;base64,${base64}`;
+      } catch (err) {
+        console.warn(`⚠️ Could not load image prompt: ${err}`);
+      }
+    }
+
+    // Default to the requested nano-banana-pro model unless explicitly provided
+    const model = options?.model || "google/nano-banana-pro";
+
+    const output = await this.replicate.run(model as `${string}/${string}`, {
+      input: inputPayload,
     });
 
     // Replicate returns a ReadableStream for the output of flux-1.1-pro in newer Node SDKs