Add example environment variables for CrownCode backend configuration

.env.example

@@ -0,0 +1,30 @@
+# CrownCode Backend Environment Variables
+# Copy this file to .env and fill in your values
+
+# =============================================
+# CORS Configuration
+# =============================================
+CROWNCODE_CORS_ORIGINS=http://localhost:3000,https://crowncode.netlify.app
+
+# =============================================
+# Logging
+# =============================================
+LOG_LEVEL=INFO
+
+# =============================================
+# Crown Commend (YouTube AI Comment Generator)
+# =============================================
+# Gemini API Key - Get from https://ai.google.dev/
+COMMEND_GEMINI_API_KEY=your-gemini-api-key-here
+
+# YouTube OAuth Token JSON - Required for posting comments
+# This is a JSON string containing YouTube OAuth credentials
+# Get this by running OAuth flow locally first
+COMMEND_TOKEN_JSON='{"token": "...", "refresh_token": "...", "token_uri": "https://oauth2.googleapis.com/token", "client_id": "...", "client_secret": "...", "scopes": ["https://www.googleapis.com/auth/youtube.force-ssl"]}'
+
+# =============================================
+# HuggingFace Spaces Specific
+# =============================================
+# These are automatically set by HuggingFace Spaces
+# HF_HOME=/app/.cache
+# TRANSFORMERS_CACHE=/app/.cache