feat(engine): wire AnimSpeed to animation, new achievements, leaderboard opt-in, daily goal display

- AnimSpeed setting now drives card slide duration (Normal=0.15s, Fast=0.07s, Instant=snap);
  EffectiveSlideDuration resource updated on SettingsChangedEvent; AnimSpeed row added to Settings panel
- GameState.recycle_count tracks waste recycles; perfectionist/comeback/zen_winner achievements added
  with full unit tests
- SyncProvider gains opt_in_leaderboard(); SolitaireServerClient implements POST /api/leaderboard/opt-in;
  Opt In button added to leaderboard panel
- DailyChallengeResource stores goal_description/target_score/max_time_secs from server;
  pressing C shows goal description as toast (DailyGoalAnnouncementEvent)

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

solitaire_data/src/lib.rs

@@ -41,6 +41,11 @@ pub trait SyncProvider: Send + Sync {
     async fn fetch_daily_challenge(&self) -> Result<Option<ChallengeGoal>, SyncError> {
         Ok(None)
     }
+    /// Opt the authenticated player into the leaderboard with the given
+    /// display name. No-op for backends that don't support leaderboards.
+    async fn opt_in_leaderboard(&self, _display_name: &str) -> Result<(), SyncError> {
+        Ok(())
+    }
 }
 
 /// Blanket impl so `Box<dyn SyncProvider + Send + Sync>` (returned by
@@ -68,6 +73,9 @@ impl SyncProvider for Box<dyn SyncProvider + Send + Sync> {
     async fn fetch_daily_challenge(&self) -> Result<Option<ChallengeGoal>, SyncError> {
         (**self).fetch_daily_challenge().await
     }
+    async fn opt_in_leaderboard(&self, display_name: &str) -> Result<(), SyncError> {
+        (**self).opt_in_leaderboard(display_name).await
+    }
 }
 
 pub mod stats;

solitaire_data/src/sync_client.rs

@@ -225,6 +225,42 @@ impl SyncProvider for SolitaireServerClient {
         }
     }
 
+    async fn opt_in_leaderboard(&self, display_name: &str) -> Result<(), SyncError> {
+        let token = self.access_token()?;
+        let url = format!("{}/api/leaderboard/opt-in", self.base_url);
+
+        let resp = self
+            .client
+            .post(&url)
+            .bearer_auth(&token)
+            .json(&serde_json::json!({ "display_name": display_name }))
+            .send()
+            .await
+            .map_err(|e| SyncError::Network(e.to_string()))?;
+
+        if resp.status() == reqwest::StatusCode::UNAUTHORIZED {
+            self.refresh_token().await?;
+            let new_token = self.access_token()?;
+            let resp = self
+                .client
+                .post(&url)
+                .bearer_auth(new_token)
+                .json(&serde_json::json!({ "display_name": display_name }))
+                .send()
+                .await
+                .map_err(|e| SyncError::Network(e.to_string()))?;
+            if !resp.status().is_success() {
+                return Err(SyncError::Auth(format!("opt-in failed: {}", resp.status())));
+            }
+            return Ok(());
+        }
+
+        if !resp.status().is_success() {
+            return Err(SyncError::Auth(format!("opt-in failed: {}", resp.status())));
+        }
+        Ok(())
+    }
+
     async fn fetch_leaderboard(&self) -> Result<Vec<LeaderboardEntry>, SyncError> {
         let token = self.access_token()?;
         let url = format!("{}/api/leaderboard", self.base_url);