fix(engine,server): safe area clamp, analytics batch, achievement save order, daily rollover, replay validation, leaderboard opt-in (#56, #60, #61, #62, #66, #68)

- #66: Clamp safe-area insets to 25% of window height with warn!() on excess
- #68: Move fire_flush outside per-event loop in analytics (batch flush once)
- #56: Persist progress before marking reward_granted to prevent XP loss on crash
- #60: Add DateRolloverTimer + check_date_rollover system for midnight seed refresh
- #62: Add validate_header() in replay upload with mode/draw_mode allowlists
- #61: Restore two-query leaderboard opt-in check (SELECT then UPDATE); original
       queries already in .sqlx cache; EXISTS variant would require sqlx prepare

Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>

solitaire_sync/src/stats.rs

@@ -54,7 +54,6 @@ pub struct StatsSnapshot {
     // `Default::default()` — and `u64::default()` is 0. The merge logic
     // and the UI must therefore treat 0 as "no win recorded yet".
     // -----------------------------------------------------------------
-
     /// Best single score achieved in Classic mode (Draw-One or Draw-Three).
     /// 0 means "no Classic win yet".
     #[serde(default)]
@@ -191,16 +190,29 @@ mod tests {
 
     #[test]
     fn record_abandoned_resets_win_streak() {
-        let mut s = StatsSnapshot { win_streak_current: 5, ..Default::default() };
+        let mut s = StatsSnapshot {
+            win_streak_current: 5,
+            ..Default::default()
+        };
         s.record_abandoned();
-        assert_eq!(s.win_streak_current, 0, "abandoned game must break the win streak");
+        assert_eq!(
+            s.win_streak_current, 0,
+            "abandoned game must break the win streak"
+        );
     }
 
     #[test]
     fn record_abandoned_preserves_best_streak() {
-        let mut s = StatsSnapshot { win_streak_best: 7, win_streak_current: 7, ..Default::default() };
+        let mut s = StatsSnapshot {
+            win_streak_best: 7,
+            win_streak_current: 7,
+            ..Default::default()
+        };
         s.record_abandoned();
-        assert_eq!(s.win_streak_best, 7, "best streak must not be reduced on abandon");
+        assert_eq!(
+            s.win_streak_best, 7,
+            "best streak must not be reduced on abandon"
+        );
         assert_eq!(s.win_streak_current, 0);
     }