Add Playwright fixtures with 5 test user types for e2e tests

Creates test infrastructure to enable previously skipped e2e tests:
- Onboarding user (no period data) for setup flow tests
- Established user (period 14 days ago) for normal usage tests
- Calendar user (with calendarToken) for ICS feed tests
- Garmin user (valid tokens) for connected state tests
- Garmin expired user (expired tokens) for expiry warning tests

Also fixes ICS feed route to strip .ics suffix from Next.js dynamic
route param, adds calendarToken to /api/user response, and sets
viewRule on users collection for unauthenticated ICS access.

Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>

src/app/api/user/route.ts

@@ -36,6 +36,7 @@ export const GET = withAuth(async (_request, user, pb) => {
       notificationTime: freshUser.notificationTime,
       timezone: freshUser.timezone,
       activeOverrides: freshUser.activeOverrides ?? [],
+      calendarToken: (freshUser.calendarToken as string) || null,
     },
     {
       headers: { "Cache-Control": "no-store, no-cache, must-revalidate" },