feat: add ShieldAI theme system with auto-shifting CSS and useTheme hook

web/vitest.config.ts

@@ -0,0 +1,13 @@
+import { defineConfig } from "vitest/config";
+import { resolve } from "path";
+
+export default defineConfig({
+  test: {
+    environment: "jsdom",
+  },
+  resolve: {
+    alias: {
+      "~": resolve(__dirname, "./src"),
+    },
+  },
+});