Refactor project structure and update configurations. Now first working version

- Updated `.air.conf` for Nix compatibility and simplified build commands.
- Enhanced `.gitignore` to include `tmp` directory.
- Improved `README.md` with clearer instructions and added language details.
- Refined CSS styles for better UI consistency and added alert styles.
- Upgraded `flake.nix` to use Go 1.24 and improved shell environment setup.
- Modified authentication logic in `auth.go` for better user handling.
- Updated `main.go` to dynamically set the listening port and improved logging.
- Added new `routes.go` file for handling game entry and history.
- Enhanced user models and added statistics tracking in `models.go`.
- Improved template rendering and added user feedback messages in HTML templates.
- Removed obsolete build error logs and binaries.

templates/leaderboard.html

@@ -3,7 +3,7 @@
     <h2>Leaderboard (by wins)</h2>
     <ol>
         {{range .Rows}}
-        <li>@<a href="/u/{{.Slug}}">{{.Username}}</a> \u2014 {{.Wins}} wins ({{.Games}} games)</li>
+        <li>@<a href="/u/{{.Slug}}">{{.Username}}</a> - {{.Wins}} wins ({{.Games}} games)</li>
         {{else}}
         <li class="small">No players yet.</li>
         {{end}}