Update .env.example with canopywave key example

Author: jahooma

.env.example

@@ -4,6 +4,7 @@ OPEN_ROUTER_API_KEY=dummy_openrouter_key
 OPENAI_API_KEY=dummy_openai_key
 ANTHROPIC_API_KEY=dummy_anthropic_key
 FIREWORKS_API_KEY=dummy_fireworks_key
+CANOPYWAVE_API_KEY=dummy_canopywave_key
 
 # Database & Server
 DATABASE_URL=postgresql://manicode_user_local:secretpassword_local@localhost:5432/manicode_db_local