# Boot NTP Auto-Sync Feature

## Task
Add a "Auto Sync on Boot" toggle in Clock Settings that silently syncs time via WiFi/NTP during boot, with no user interaction required and graceful failure handling.

## Changes Made

### New files
- `src/util/BootNtpSync.h` / `src/util/BootNtpSync.cpp` -- Background FreeRTOS task that scans WiFi, connects to a saved network, runs NTP sync, then tears down WiFi. Provides `start()`, `cancel()`, and `isRunning()` API.

### Modified files
- `src/CrossPointSettings.h` -- Added `uint8_t autoNtpSync = 0` field
- `src/CrossPointSettings.cpp` -- Added persistence (write/read) for the new field
- `src/SettingsList.h` -- Added Toggle entry under Clock category
- `lib/I18n/translations/*.yaml` (all 9 languages) -- Added `STR_AUTO_NTP_SYNC` string
- `lib/I18n/I18nKeys.h` / `lib/I18n/I18nStrings.cpp` -- Regenerated via `gen_i18n.py`
- `src/main.cpp` -- Calls `BootNtpSync::start()` during setup (non-blocking)
- `src/activities/settings/NtpSyncActivity.cpp` -- Added `BootNtpSync::cancel()` guard
- `src/activities/network/WifiSelectionActivity.cpp` -- Added cancel guard
- `src/activities/settings/OtaUpdateActivity.cpp` -- Added cancel guard
- `src/activities/settings/KOReaderAuthActivity.cpp` -- Added cancel guard
- `src/activities/reader/KOReaderSyncActivity.cpp` -- Added cancel guard
- `src/activities/network/CrossPointWebServerActivity.cpp` -- Added cancel guard

## Follow-up Items
- Translations: all non-English languages currently use English fallback for the new string
- The FreeRTOS task uses 4096 bytes of stack; monitor for stack overflow if WiFi scan behavior changes
- WiFi adds ~50-60KB RAM pressure during the sync window (temporary)