Refactor timerWakeCycle() to fetch a single random photo per wake
using cycle-mode-aware server-side filtering via Immich's
POST /api/search/random endpoint.
Changes:
- Add fetchOneRandomAssetId() to ImmichClient with support for
isFavorite, takenAfter, takenBefore filter parameters
- Add timer_last_date NVS field for chronological cursor persistence
- Implement probabilistic filter selection per cycle mode:
- Random: unfiltered size=1
- Chronological/ReverseChronological: date cursor in NVS
- FavoritesWeighted: 66% favorites, 33% unfiltered
- WeightedChronological: 66% recent (30d), 33% unfiltered
- WeightedReverseChronological: 66% older (30d), 33% unfiltered
- Add retry loop with filter relaxation on empty results
- Initialize hardware RTC (RX8130CE) firmware-wide:
- Seed system clock from RTC at boot (immediate time)
- NTP sync after WiFi connect, write back to RTC
- Add time_utils.h with isoNow(), isoNowMinus30d(), hasValidTime()
Normal mode (PhotoQueue + displayTask) is completely untouched.
Co-authored-by: Cursor <cursoragent@cursor.com>
