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/curves.rs

@@ -126,7 +126,12 @@ mod tests {
             MotionCurve::Responsive,
             MotionCurve::Expressive,
         ] {
-            assert_near(sample_curve(curve, 0.0), 0.0, 1e-5, &format!("{curve:?} at t=0"));
+            assert_near(
+                sample_curve(curve, 0.0),
+                0.0,
+                1e-5,
+                &format!("{curve:?} at t=0"),
+            );
         }
     }
 
@@ -137,7 +142,12 @@ mod tests {
             MotionCurve::SoftBounce,
             MotionCurve::Responsive,
         ] {
-            assert_near(sample_curve(curve, 1.0), 1.0, 1e-4, &format!("{curve:?} at t=1"));
+            assert_near(
+                sample_curve(curve, 1.0),
+                1.0,
+                1e-4,
+                &format!("{curve:?} at t=1"),
+            );
         }
         // Spring-based curves have residual oscillation at finite t=1; allow 2 e-3.
         assert_near(
@@ -159,8 +169,14 @@ mod tests {
     fn smooth_snap_overshoots_slightly_near_end() {
         // Peak overshoot is around t = 0.875.
         let peak = sample_curve(MotionCurve::SmoothSnap, 0.875);
-        assert!(peak > 1.0, "SmoothSnap should overshoot at t=0.875, got {peak}");
-        assert!(peak < 1.03, "SmoothSnap overshoot should be small (<3 %), got {peak}");
+        assert!(
+            peak > 1.0,
+            "SmoothSnap should overshoot at t=0.875, got {peak}"
+        );
+        assert!(
+            peak < 1.03,
+            "SmoothSnap overshoot should be small (<3 %), got {peak}"
+        );
     }
 
     #[test]
@@ -186,11 +202,21 @@ mod tests {
 
     #[test]
     fn sample_curve_clamps_t_below_zero() {
-        assert_near(sample_curve(MotionCurve::SmoothSnap, -1.0), 0.0, 1e-5, "t<0 clamped");
+        assert_near(
+            sample_curve(MotionCurve::SmoothSnap, -1.0),
+            0.0,
+            1e-5,
+            "t<0 clamped",
+        );
     }
 
     #[test]
     fn sample_curve_clamps_t_above_one() {
-        assert_near(sample_curve(MotionCurve::Responsive, 2.0), 1.0, 1e-5, "t>1 clamped");
+        assert_near(
+            sample_curve(MotionCurve::Responsive, 2.0),
+            1.0,
+            1e-5,
+            "t>1 clamped",
+        );
     }
 }