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/feedback_anim_plugin.rs

@@ -849,8 +849,8 @@ mod tests {
     #[test]
     fn shake_anim_skipped_under_reduce_motion() {
         use bevy::ecs::message::Messages;
-        use solitaire_core::game_state::{DrawMode, GameState};
         use klondike::Tableau;
+        use solitaire_core::game_state::{DrawMode, GameState};
         use solitaire_data::Settings;
 
         let mut app = App::new();