## Why
MCP startup status delivery can lag. Treating a server that is still starting or
has not reported yet as cancelled produces a misleading interruption warning and
can hide its eventual terminal result.
## What changed
- Only report an interrupted startup when a server explicitly enters the
cancelled state.
- Allow a complete set of terminal updates received after the lag timeout to be
promoted and reported, including failures and cancellations.
## Testing
Added TUI tests covering unresolved servers at the lag timeout and late failure
and cancellation updates.
GitOrigin-RevId: 555f3d13ac87bda6e9b0bf72335a1c04851ac25a