feat: add dark theme support and increase contrast

frontend/src/theme/Theme.ts

@@ -17,17 +17,20 @@
  * You should have received a copy of the GNU General Public License
  * along with this program. If not, see <http://www.gnu.org/licenses/>.
  */
-import { createTheme } from "@mui/material/styles";
+import { createTheme, type Theme } from "@mui/material/styles";
 
-const Theme = createTheme({
-    components: {
-        MuiDialog: {
-            defaultProps: {
-                maxWidth: "lg",
-                fullWidth: true,
+export function createAppTheme(mode: "light" | "dark"): Theme {
+    return createTheme({
+        palette: {
+            mode,
+        },
+        components: {
+            MuiDialog: {
+                defaultProps: {
+                    maxWidth: "lg",
+                    fullWidth: true,
+                },
             },
         },
-    },
-});
-
-export default Theme;
+    });
+}