[Tracker] Schedule component — Q3 maturation (interaction, docs, graduation path)

## Problem

`@astryxdesign/lab` ships a `Schedule` component — a read-only calendar shell with Day / Week / Month / List / TimeGrid views, a plugin system (pagination, view selector), timezone-aware date math, and a full event/type surface. It's a solid foundation, but it's incomplete as a first-class scheduling surface: it's read-only, its `.doc.mjs` carries no usage description or documented props, and it hasn't been through the graduation review that would move it from `lab` toward `core`.

This is a **tracker** for the Q3 push to mature the Schedule components. Individual enhancements are filed and linked below; each lands on its own via the normal issue → API → PR flow.

## Scope — starter set (on this milestone)

- [ ] Documentation — fill in `Schedule.doc.mjs` (usage description + props), Storybook coverage per view
- [ ] Event interaction — event selection / click affordances (read → interactive)
- [ ] Event mutation — create / edit / move (drag) events with controlled callbacks
- [ ] Accessibility pass — keyboard navigation across grid views, ARIA roles, focus management
- [ ] View parity — audit Day/Week/Month/List/TimeGrid for consistent options + plugin support
- [ ] Graduation criteria — define what "core-ready" means for Schedule (API arbitration, test coverage, docs)

## Notes

This is a starting set — scope to be adjusted as priorities firm up. Each sub-item follows the spec protocol independently (problem → research → API → PR). This issue only tracks the theme so the milestone reflects "Schedule component" as one major line of work.

Treat this as a tracker rather than a standalone implementation task, and start with the linked individual enhancements. Read Schedule.doc.mjs and the existing Storybook coverage for the views, then follow the spec protocol for one scoped item; done means that item's API, tests, documentation, or accessibility criteria are agreed and landed independently.

Written by the indexing model from the issue text.