When a channel is configured with dmPolicy="open" but without
allowFrom: ["*"], the gateway rejects the config and exits.
The error message suggests running "openclaw doctor --fix", but
the doctor had no repair logic for this case.
This adds a repair step that automatically adds "*" to allowFrom
(or creates it) when dmPolicy="open" is set without the required
wildcard. Handles both top-level and nested dm.allowFrom, as well
as per-account configs.
Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>