Conflict resolution left webui/lease_loader.py importing ISSUE_LOCK_FILE
from merged_cleanup_reconcile (not exported); import from
issue_lock_provenance instead. Validate WEBUI_HOST before loading the
full app stack so 0.0.0.0 refuse exits immediately.
Addresses reviewer findings on PR #456 / issue #435.
Add bind-host assessment that refuses 0.0.0.0/:: without override,
warns on non-loopback binds, and documents internal-only MVP serving.
Health endpoint exposes deployment metadata; docs cover Access/VPN/WARP
and runtime env assumptions without embedding secrets in the client.
Closes#435