fix: restore dark theme and fix theme script regex

Dark theme was set to "dim" in theme.config.ts while app.css registered
"sunset" as the prefersdark theme. The script's regex required a trailing
comma that didn't exist on the last property, causing silent failures.

_scripts/change-theme-dark.ts

@@ -28,8 +28,8 @@ let themeConfigContent = readFileSync(themeConfigPath, "utf8")
 
 // Remplacer la valeur du thème sombre
 themeConfigContent = themeConfigContent.replace(
-  /dark:\s*['"][^'"]*['"],/,
-  `dark: '${newTheme}',`
+  /dark:\s*['"][^'"]*['"](,?)/,
+  `dark: '${newTheme}'$1`
 )
 
 // Écrire le contenu mis à jour dans le fichier