feat(02-01): schema columns, PWA vitest harness, ICS fixtures, RED test stubs

- Add calendarEvents.hasRrule boolean + idx_calendar_events_has_rrule index (Phase 2 pre-filter)
- Add calendars.isShared boolean for shared-family calendar identification
- Create apps/pwa/vitest.config.ts with jsdom environment
- Add vitest, @testing-library/react, jsdom, @testing-library/jest-dom to PWA devDependencies
- Add "test": "vitest run" script to apps/pwa/package.json
- Create three ICS fixtures: weekly-dst.ics (DST spanning), allday-birthday.ics, exdate-series.ics
- Create RED test stub expand.test.ts with concrete DST wall-clock assertions (10:00 local both sides of March 2026 boundary)
- Create RED test stub events.test.ts with 400 validation and color/isShared field contracts
- Create RED test stub hydrateEvents.test.ts with Temporal type and calendarId routing contracts (shared→"shared", personal→String(ownerUserId))
- Create RED test stub calendarConfig.test.ts with firstDayOfWeek 0→7 translation contract

apps/pwa/vitest.config.ts

@@ -0,0 +1,8 @@
+import { defineConfig } from 'vitest/config'
+
+export default defineConfig({
+  test: {
+    environment: 'jsdom',
+    globals: true,
+  },
+})