Menu bar status logic and what is surfaced to users
What is shown
We surface the current agent work state in the menu bar icon and in the first status row of the menu.
Health status is hidden while work is active; it returns when all sessions are idle.
A root "Context" submenu contains recent sessions instead of expanding them directly in the root menu.
The "Nodes" block in the root menu lists devices only (paired nodes via node.list), not client/presence entries.
A root "Usage" section appears below Context when provider usage snapshots are available, followed by usage-cost details when available.
State model
Sessions: events arrive with runId (per-run) plus sessionKey in the payload. The "main" session is the key main; if absent, we fall back to the most recently updated session.
Priority: main always wins. If main is active, its state is shown immediately. If main is idle, the most recently active non-main session is shown. We do not flip-flop mid-activity; we only switch when the current session goes idle or main becomes active.