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_assetgen/src/bin/gen_difficulty_seeds.rs

@@ -20,15 +20,15 @@
 //!   --help      Print this message
 
 use solitaire_core::game_state::DrawMode;
-use solitaire_core::solver::{try_solve, SolverConfig, SolverResult};
+use solitaire_core::solver::{SolverConfig, SolverResult, try_solve};
 
 // Budget boundaries defining each tier. A seed belongs to the lowest tier
 // whose budget proves it Winnable.
 const BUDGETS: &[(&str, u64, usize)] = &[
-    ("Easy",        1_000,   1_000),
-    ("Medium",      5_000,   5_000),
-    ("Hard",       25_000,  25_000),
-    ("Expert",    100_000, 100_000),
+    ("Easy", 1_000, 1_000),
+    ("Medium", 5_000, 5_000),
+    ("Hard", 25_000, 25_000),
+    ("Expert", 100_000, 100_000),
     ("Grandmaster", 200_000, 200_000),
 ];
 
@@ -86,7 +86,11 @@ fn main() {
     );
     eprintln!(
         "  Tiers: {}",
-        BUDGETS.iter().map(|(n, _, _)| *n).collect::<Vec<_>>().join(", ")
+        BUDGETS
+            .iter()
+            .map(|(n, _, _)| *n)
+            .collect::<Vec<_>>()
+            .join(", ")
     );
 
     while buckets.iter().any(|b| b.len() < per_tier) {
@@ -95,7 +99,10 @@ fn main() {
             if buckets[i].len() >= per_tier {
                 continue;
             }
-            let cfg = SolverConfig { move_budget, state_budget };
+            let cfg = SolverConfig {
+                move_budget,
+                state_budget,
+            };
             match try_solve(seed, draw_mode, &cfg) {
                 SolverResult::Winnable => {
                     buckets[i].push(seed);
@@ -123,7 +130,9 @@ fn main() {
         seed = seed.wrapping_add(1);
     }
 
-    eprintln!("\nDone ({tried} seeds examined). Paste the blocks below into difficulty_seeds.rs:\n");
+    eprintln!(
+        "\nDone ({tried} seeds examined). Paste the blocks below into difficulty_seeds.rs:\n"
+    );
 
     let date = current_date();
     for (i, (tier_name, _, _)) in BUDGETS.iter().enumerate() {
@@ -148,7 +157,10 @@ fn main() {
 
 fn parse_u64(s: &str) -> u64 {
     let cleaned = s.replace('_', "");
-    if let Some(hex) = cleaned.strip_prefix("0x").or_else(|| cleaned.strip_prefix("0X")) {
+    if let Some(hex) = cleaned
+        .strip_prefix("0x")
+        .or_else(|| cleaned.strip_prefix("0X"))
+    {
         u64::from_str_radix(hex, 16).unwrap_or_else(|_| {
             eprintln!("error: could not parse '{s}' as a hex u64");
             std::process::exit(1);
@@ -181,7 +193,18 @@ fn current_date() -> String {
     }
     let leap = (y.is_multiple_of(4) && !y.is_multiple_of(100)) || y.is_multiple_of(400);
     let month_days: [u64; 12] = [
-        31, if leap { 29 } else { 28 }, 31, 30, 31, 30, 31, 31, 30, 31, 30, 31,
+        31,
+        if leap { 29 } else { 28 },
+        31,
+        30,
+        31,
+        30,
+        31,
+        31,
+        30,
+        31,
+        30,
+        31,
     ];
     let mut m = 0usize;
     for &md in &month_days {