chore(workspace): fix all clippy warnings in test code

Resolves 15 violations found by `cargo clippy --workspace --tests -D warnings`:
- Remove unused imports (Card, Rank) in cursor_plugin tests
- Replace absurd i32::MAX comparison with a meaningful >= 0 check
- Use range .contains() instead of manual >= && <= (manual_range_contains)
- Move impl FromRequestParts before test module in middleware.rs (items_after_test_module)
- Move _VEC3_REFERENCED const before test module in input_plugin.rs
- Convert runtime assert on constant to const { assert!(...) }
- Use .contains() instead of .iter().any() for slice membership
- Replace .get(...).is_none() with !.contains_key(...) in HashMap checks
- Collapse Default::default() + field assignment into struct literal initializers
  across solitaire_sync, solitaire_data, and solitaire_engine test helpers

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

solitaire_sync/src/progress.rs

@@ -201,8 +201,7 @@ mod tests {
 
     #[test]
     fn add_xp_saturates_on_overflow() {
-        let mut p = PlayerProgress::default();
-        p.total_xp = u64::MAX;
+        let mut p = PlayerProgress { total_xp: u64::MAX, ..Default::default() };
         p.add_xp(1);
         assert_eq!(p.total_xp, u64::MAX);
     }
@@ -230,8 +229,7 @@ mod tests {
 
     #[test]
     fn roll_weekly_goals_clears_progress_for_new_week() {
-        let mut p = PlayerProgress::default();
-        p.weekly_goal_week_iso = Some("2026-W16".to_string());
+        let mut p = PlayerProgress { weekly_goal_week_iso: Some("2026-W16".to_string()), ..Default::default() };
         p.weekly_goal_progress.insert("weekly_5_wins".to_string(), 3);
 
         let rolled = p.roll_weekly_goals_if_new_week("2026-W17");
@@ -242,8 +240,7 @@ mod tests {
 
     #[test]
     fn roll_weekly_goals_is_noop_for_same_week() {
-        let mut p = PlayerProgress::default();
-        p.weekly_goal_week_iso = Some("2026-W17".to_string());
+        let mut p = PlayerProgress { weekly_goal_week_iso: Some("2026-W17".to_string()), ..Default::default() };
         p.weekly_goal_progress.insert("weekly_5_wins".to_string(), 2);
 
         let rolled = p.roll_weekly_goals_if_new_week("2026-W17");

solitaire_sync/src/stats.rs

@@ -135,17 +135,14 @@ mod tests {
 
     #[test]
     fn record_abandoned_resets_win_streak() {
-        let mut s = StatsSnapshot::default();
-        s.win_streak_current = 5;
+        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");
     }
 
     #[test]
     fn record_abandoned_preserves_best_streak() {
-        let mut s = StatsSnapshot::default();
-        s.win_streak_best = 7;
-        s.win_streak_current = 7;
+        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_current, 0);