feat(frontend): redo setup with ts+tailwind and implement auth+header

frontend/postcss.config.js

@@ -0,0 +1,15 @@
+const purgecss = require("@fullhuman/postcss-purgecss")({
+  // Specify the paths to all of the template files in your project
+  content: ["./public/**/*.html", "./src/**/*.tsx"],
+
+  // Include any special characters you're using in this regular expression
+  defaultExtractor: content => content.match(/[\w-/:]+(?<!:)/g) || []
+});
+
+module.exports = {
+  plugins: [
+    require("tailwindcss"),
+    require("autoprefixer"),
+    ...(process.env.NODE_ENV === "production" ? [purgecss] : [])
+  ]
+};