chore: cargo fmt across workspace; add analytics domain to CSP

- Apply cargo fmt to solitaire_engine, solitaire_server formatting.
- solitaire_server/src/lib.rs: add https://analytics.aleshym.co to
  script-src, img-src, and connect-src so the analytics beacon loads
  without a CSP violation.
- docs and README updates.

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

solitaire_engine/src/daily_challenge_plugin.rs

@@ -13,10 +13,10 @@
 
 use bevy::input::ButtonInput;
 use bevy::prelude::*;
-use chrono::{DateTime, Duration, Local, NaiveDate, Utc};
-use solitaire_data::{daily_seed_for, save_progress_to};
 #[cfg(not(target_arch = "wasm32"))]
 use bevy::tasks::{AsyncComputeTaskPool, Task, futures_lite::future};
+use chrono::{DateTime, Duration, Local, NaiveDate, Utc};
+use solitaire_data::{daily_seed_for, save_progress_to};
 #[cfg(not(target_arch = "wasm32"))]
 use solitaire_sync::ChallengeGoal;
 
@@ -354,7 +354,6 @@ fn check_date_rollover(
     }
 }
 
-
 #[cfg(test)]
 #[allow(dead_code)]
 mod tests {