fix(copilot): default SIM_AGENT_API_URL to www.copilot.sim.ai to avoid redirect path drop (#4700)

Author: waleedlatif1

apps/sim/lib/copilot/constants.ts

@@ -1,6 +1,6 @@
 import { env } from '@/lib/core/config/env'
 
-export const SIM_AGENT_API_URL_DEFAULT = 'https://copilot.sim.ai'
+export const SIM_AGENT_API_URL_DEFAULT = 'https://www.copilot.sim.ai'
 export const SIM_AGENT_VERSION = '3.0.0'
 
 /** Resolved copilot backend URL — reads from env with fallback to default. */