Internally, the status bar spinner state (responding/thinking/tool-input, compacting status, turn effort) is now tracked per agent ID in a keyed store instead of a single global singleton. This is a prerequisite for correct multi-agent displays where parallel agents each need their own status line. Spinner state for removed agents is cleaned up automatically.
Evidence
Per-agent state store (search for "defaultVerb" in spinner state initialization) and per-agent accessor (search for "n64(H.agentId)")
Strings lifted out of the shipped bundle, so the claim above can be checked against them.