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_engine/src/card_animation/timing.rs

@@ -88,7 +88,10 @@ mod tests {
         let mut prev = 0.0f32;
         for d in [10, 50, 100, 200, 400, 600] {
             let dur = compute_duration(d as f32);
-            assert!(dur >= prev, "duration must be monotone: d={d} dur={dur} prev={prev}");
+            assert!(
+                dur >= prev,
+                "duration must be monotone: d={d} dur={dur} prev={prev}"
+            );
             prev = dur;
         }
     }
@@ -129,7 +132,10 @@ mod tests {
         let a = micro_vary(0.2, 1);
         let b = micro_vary(0.2, 2);
         // Very unlikely to be equal (would require hash collision mod 65536).
-        assert!((a - b).abs() > 1e-9, "micro_vary should differ for different indices");
+        assert!(
+            (a - b).abs() > 1e-9,
+            "micro_vary should differ for different indices"
+        );
     }
 
     #[test]