feat(settings/user/color): implement basic color picker without animations

app/stores/app.ts

@@ -1,5 +1,20 @@
 export const useAppStore = defineStore("app", {
   state: () => ({
     booted: false,
+    _color: { col: 0, row: 0 },
   }),
+
+  actions: {
+    setColor(col: number, row: number) {
+      this._color = { col, row };
+    },
+  },
+
+  getters: {
+    color: (state) => ({
+      col: state._color.col,
+      row: state._color.row,
+      hex: APP_COLORS[state._color.row]![state._color.col]!,
+    }),
+  },
 });