"Event" resource kind

It would be nice to work with various events using the app.

Events like meetings, reminders or alarm clock. Special "calendar" and "chronology" views would be appropriate for those.
When a selection contains only resources of "event" type, the grid should be replaced with dedicated view.
When a selection contains such resources but not only, screen can be split into two halves: normal grid and dedicated view.

Storage format is open question (possible to batch events into 1 file, or support both batched and separate formats).

The issue proposes an Event resource kind, calendar and chronology views, mixed-selection splitting, and multiple possible storage formats, but names no files, tests, or entry points. First clarify the storage format and UI behavior, then identify the existing resource and grid-view entry points; done means event resources can be stored, selected, and displayed as specified.

Written by the indexing model from the issue text.