The MCP Worker hardcoded https://api.honcho.dev for every request, forcing
anyone running a self-hosted Honcho instance to patch the source before
deploying their own Worker alongside it.
Route the baseUrl through the Worker env so operators can set
HONCHO_API_URL (via .dev.vars for local development or wrangler secret for
deployed Workers) and point the Worker at their instance. The variable is
intentionally not exposed as a request header: that would let public
clients steer traffic to internal URLs, which is a latency and security
regression.
When HONCHO_API_URL is unset, the Worker falls back to
https://api.honcho.dev, so existing deployments are unaffected.
Closes#508
Alfredo Colangelo