Hermes ACP _restore fails for custom providers — resolve_runtime_provider
throws and base_url/api_mode are lost, causing resume to silently create a
new session with no history. Prompt then returns empty text or refusal.
Disable resume by default. Set UWF_HERMES_RESUME=1 to opt back in.
Includes investigation notes in docs/investigations/.
Refs #418
xiaoju
aad2792754