Add a shared transparent OrganizationAgentConfigFolder tree for grouping
agent roles and skills in the admin UI without affecting identity, bindings,
run loading, or slash commands.
- Add buildOutboundPayload: detect markdown format, isolate code blocks,
force plain text for tables, fallback from post to text on API rejection
- Add addReaction/removeReaction for processing status lifecycle
- Replace THUMBSUP with Typing→(remove on success | CrossMark on failure)
- Add unit tests for markdown rendering (15) and reactions (6)