feat: Implement image caching for game covers, enhance frontend game list item layout, add Factorio to the game list, and ignore the cache directory.

backend/src/main.rs

@@ -123,6 +123,26 @@ async fn get_game_thumbnail(
     title: &str,
     game_list: &rocket::State<Mutex<Vec<Game>>>,
 ) -> Option<(rocket::http::ContentType, Vec<u8>)> {
+    // 1. Sanitize title for filename
+    let safe_title: String = title
+        .chars()
+        .map(|c| if c.is_alphanumeric() { c } else { '_' })
+        .collect();
+
+    let cache_dir = "cache";
+    let _ = std::fs::create_dir_all(cache_dir);
+    let cache_path_bin = format!("{}/{}.bin", cache_dir, safe_title);
+    let cache_path_type = format!("{}/{}.type", cache_dir, safe_title);
+
+    // 2. Check cache
+    if let (Ok(bytes), Ok(type_str)) = (
+        std::fs::read(&cache_path_bin),
+        std::fs::read_to_string(&cache_path_type),
+    ) && let Some(ct) = rocket::http::ContentType::parse_flexible(&type_str)
+    {
+        return Some((ct, bytes));
+    }
+
     let games = game_list.lock().await;
     let game = games.iter().find(|g| g.title == title)?;
 
@@ -174,6 +194,11 @@ async fn get_game_thumbnail(
                 .and_then(rocket::http::ContentType::parse_flexible)
                 .unwrap_or(rocket::http::ContentType::Binary);
             let bytes = resp.bytes().await.ok()?.to_vec();
+
+            // 3. Write to cache
+            let _ = std::fs::write(&cache_path_bin, &bytes);
+            let _ = std::fs::write(&cache_path_type, content_type.to_string());
+
             Some((content_type, bytes))
         }
         Err(_) => None,