Migrate to tsgo

src/lib/mui/MuiStyles.types.d.ts

@@ -12,4 +12,11 @@ declare module '@mui/material/styles' {
     interface CssThemeVariables {
         enabled: true;
     }
+
+    // Re-exported here because MUI doesn't include PaletteBackgroundChannel in its public API surface.
+    // Defined in @mui/material/esm/styles/createThemeFoundation.d.ts
+    export interface PaletteBackgroundChannel {
+        defaultChannel: string;
+        paperChannel: string;
+    }
 }