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/ui_theme.rs

@@ -294,7 +294,10 @@ impl HighContrastBackground {
     /// Convenience constructor — HC colour defaults to
     /// [`BORDER_SUBTLE_HC`].
     pub const fn with_default(default_color: bevy::prelude::Color) -> Self {
-        Self { default_color, hc_color: BORDER_SUBTLE_HC }
+        Self {
+            default_color,
+            hc_color: BORDER_SUBTLE_HC,
+        }
     }
 
     /// Constructor for sites whose HC colour differs from the standard
@@ -305,7 +308,10 @@ impl HighContrastBackground {
         default_color: bevy::prelude::Color,
         hc_color: bevy::prelude::Color,
     ) -> Self {
-        Self { default_color, hc_color }
+        Self {
+            default_color,
+            hc_color,
+        }
     }
 }
 
@@ -621,7 +627,9 @@ mod tests {
     /// honest if someone tweaks values later.
     #[test]
     fn spacing_scale_is_a_4_multiple_geometric_progression() {
-        for v in [SPACE_1, SPACE_2, SPACE_3, SPACE_4, SPACE_5, SPACE_6, SPACE_7] {
+        for v in [
+            SPACE_1, SPACE_2, SPACE_3, SPACE_4, SPACE_5, SPACE_6, SPACE_7,
+        ] {
             assert!(v > 0.0, "spacing tokens must be positive");
             assert!(
                 (v.rem_euclid(4.0)).abs() < f32::EPSILON,
@@ -633,7 +641,13 @@ mod tests {
     /// Type scale is monotonically decreasing display → caption.
     #[test]
     fn type_scale_is_monotonically_decreasing() {
-        let scale = [TYPE_DISPLAY, TYPE_HEADLINE, TYPE_BODY_LG, TYPE_BODY, TYPE_CAPTION];
+        let scale = [
+            TYPE_DISPLAY,
+            TYPE_HEADLINE,
+            TYPE_BODY_LG,
+            TYPE_BODY,
+            TYPE_CAPTION,
+        ];
         for window in scale.windows(2) {
             assert!(
                 window[0] > window[1],