feat: Add NTP clock sync to Clock settings

Adds a "Sync Clock" action in Settings > Clock that connects to WiFi
(auto-connecting to saved networks or prompting for selection) and
performs a blocking NTP time sync. Shows the synced time on success
with an auto-dismiss countdown, or an error on failure.

Co-authored-by: Cursor <cursoragent@cursor.com>

lib/I18n/I18nKeys.h

@@ -398,6 +398,8 @@ enum class StrId : uint16_t {
   STR_INDEXING_POPUP,
   STR_INDEXING_STATUS_TEXT,
   STR_INDEXING_STATUS_ICON,
+  STR_SYNC_CLOCK,
+  STR_TIME_SYNCED,
   // Sentinel - must be last
   _COUNT
 };