Verify events.watch max TTL and privateExtendedProperty AND/OR

Two items still flagged as unverified in the specification, both only mattering once the return path exists.

- [ ] **Max TTL for `events.watch`.** Measure the actual `expiration` returned; adjust the daily renewal cadence if it is shorter than 7 days.
- [ ] **Whether repeated `privateExtendedProperty` filters are AND or OR.** Google's reference and guide contradict each other. Test both; record the answer here. Only relevant if Orrey ever filters by extended property (the syncToken constraint means it currently does not).