Enhance AI description generation with custom instructions for users

Add a custom instructions input field to the admin video edit dialog and backend to allow users to guide the AI description generation process.

Replit-Commit-Author: Agent
Replit-Commit-Session-Id: 170e18f0-0f13-4eca-8643-546bba1dd8cc
Replit-Commit-Checkpoint-Type: full_checkpoint
Replit-Commit-Screenshot-Url: https://storage.googleapis.com/screenshot-production-us-central1/8cc42625-c1f5-4e43-99bd-77f2c4dedee2/170e18f0-0f13-4eca-8643-546bba1dd8cc/LY6xmBI

server/routes.ts

@@ -1087,7 +1087,7 @@ export async function registerRoutes(app: Express): Promise<Server> {
   app.post('/api/admin/videos/:id/generate-description', isAdmin, async (req, res) => {
     try {
       const videoId = req.params.id;
-      const { maxCharacters = 500, includeArtistInfo = true, includeLabelInfo = true } = req.body;
+      const { maxCharacters = 500, includeArtistInfo = true, includeLabelInfo = true, customInstructions } = req.body;
       
       console.log("AI description request for video:", videoId); // Debug log
       
@@ -1103,9 +1103,10 @@ export async function registerRoutes(app: Express): Promise<Server> {
       // Generate description using AI
       const description = await generateVideoDescription(video.title, {
         maxCharacters,
-        language: "slovenian",
+        language: "german",
         includeArtistInfo,
-        includeLabelInfo
+        includeLabelInfo,
+        customInstructions
       });
       
       console.log("Generated description:", description); // Debug log