OpenClaw: Workspace dotenv files cannot override connector endpoint hosts

## Summary Workspace dotenv files cannot override connector endpoint hosts. ## Affected Packages / Versions - Package: openclaw (npm) - Affected versions: <= 2026.4.21 - Fixed version: 2026.4.22 ## Impact A workspace .env file could set connector endpoint variables for Matrix, Mattermost, IRC, or Synology-related connectors and redirect runtime traffic away from the operator-configured endpoint. ## Fix Workspace .env loading now blocks those endpoint variables, including per-account Matrix homeserver suffixes and generic base-url/API-host style overrides. Trusted global runtime dotenv loading remains separate. ## Fix Commit(s) - 0623079e98abf7202591f1b04a89755eb7ec9272 ## Verification - The fix commit is contained in the public v2026.4.22 tag. - openclaw@2026.4.22 is published on npm and the compiled package contains the fix. - Focused regression coverage for this path passed before publication. OpenClaw thanks @qi-scape for reporting.