Fix recurring exception sync for rescheduled recurring tasks

[martin-forge]

Summary

• Preserve the original RRULE occurrence date when a scheduled-anchor recurring task is moved off-pattern.
• Sync moved occurrences to Google Calendar as a recurring master with an EXDATE plus one detached exception event.
• Clean up detached exception metadata/events when the moved occurrence is completed, skipped, archived, deleted, or unlinked.
• Keep local calendar recurring rendering aligned by hiding original pattern dates represented by moved-occurrence metadata.

Closes #1696.

Validation

• TZ=UTC npm test -- --runInBand
• npm run docs:check
• npm run i18n:sync
• npm run lint
• npm run typecheck
• npm run build:test
• obsidian plugin:reload id=tasknotes vault=test