chore(deployment): add docker-compose and nginx setup for production

- Added Dockerfile and nginx.conf for frontend production build.
- Added docker-compose.yml to orchestrate backend and frontend.
- Updated geminiService.ts to support relative API paths via Nginx proxy.
- Updated documentation with deployment instructions for Synology/Docker.

general-market-intelligence/Dockerfile

@@ -0,0 +1,27 @@
+# Stage 1: Build the React App
+FROM node:18-alpine as build
+
+WORKDIR /app
+
+# Copy package files first for better caching
+COPY package.json package-lock.json ./
+RUN npm install
+
+# Copy source code
+COPY . .
+
+# Build for production
+RUN npm run build
+
+# Stage 2: Serve with Nginx
+FROM nginx:alpine
+
+# Copy built assets from Stage 1
+COPY --from=build /app/dist /usr/share/nginx/html
+
+# Copy custom Nginx config
+COPY nginx.conf /etc/nginx/conf.d/default.conf
+
+EXPOSE 80
+
+CMD ["nginx", "-g", "daemon off;"]

general-market-intelligence/nginx.conf

@@ -0,0 +1,22 @@
+server {
+    listen 80;
+    
+    # 1. Serve React Frontend (Static Files)
+    location / {
+        root /usr/share/nginx/html;
+        index index.html index.htm;
+        try_files $uri $uri/ /index.html; # Support for React Router (SPA)
+    }
+
+    # 2. Proxy API Requests to Backend Container
+    location /api/ {
+        # 'backend' is the service name in docker-compose.yml
+        # Port 3001 is where the Node.js bridge listens
+        proxy_pass http://backend:3001/api/;
+        proxy_http_version 1.1;
+        proxy_set_header Upgrade $http_upgrade;
+        proxy_set_header Connection 'upgrade';
+        proxy_set_header Host $host;
+        proxy_cache_bypass $http_upgrade;
+    }
+}

general-market-intelligence/services/geminiService.ts

@@ -3,8 +3,12 @@ import { LeadStatus, AnalysisResult, Competitor, Language, Tier, EmailDraft, Sea
 // const apiKey = process.env.API_KEY; // Nicht mehr direkt im Frontend verwendet
 // const ai = new GoogleGenAI({ apiKey: apiKey || '' }); // Nicht mehr direkt im Frontend verwendet
 
-// URL unserer lokalen Node.js API-Brücke
-const API_BASE_URL = `http://${window.location.hostname}:3001/api`; 
+// URL Konfiguration:
+// Im Production-Build (Docker/Nginx) nutzen wir den relativen Pfad '/api', da Nginx als Reverse Proxy fungiert.
+// Im Development-Modus (lokal) greifen wir direkt auf den Port 3001 zu.
+const API_BASE_URL = import.meta.env.PROD 
+  ? '/api' 
+  : `http://${window.location.hostname}:3001/api`; 
 
 // Helper to extract JSON (kann ggf. entfernt werden, wenn das Backend immer sauberes JSON liefert)
 const extractJson = (text: string): any => {