* feat(schedules): polish schedules list and editing
Adds host filtering, status grouping, and target resolution to the
schedules screen. Extracts a shared HostFilter from sessions. Improves
schedule editing with project targets and model hydration. Handles
missing targets server-side instead of retrying forever.
* test(mcp): update schedule mocks for createOrReplace
* fix(schedules): only show host name when multiple hosts exist
