upgrade tailwind

* moved to vite plugin for tailwind (it's recommended now)
* removed autoprefixer (v4 uses its own CSS thing now)
* postcss.config.js was used to wire up tailwind and autoprefixer, so
  it's gone
* tailwind.config.ts is gone, because v4 stores config in app.css using
  css variables
* fixed some renamed classes

daemon/web/vite.config.ts

@@ -1,5 +1,6 @@
 import { defineConfig } from 'vitest/config';
 import { sveltekit } from '@sveltejs/kit/vite';
+import tailwindcss from '@tailwindcss/vite';
 
 export default defineConfig({
     server: {
@@ -26,7 +27,7 @@ export default defineConfig({
             },
         },
     },
-    plugins: [sveltekit()],
+    plugins: [tailwindcss(), sveltekit()],
     build: {
         // Force everything into one HTML file. SvelteKit will still generate
         // a lot of JS files but they are deadweight and will not be included