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/package.json

@@ -20,9 +20,9 @@
         "@sveltejs/adapter-static": "^3.0.5",
         "@sveltejs/kit": "^2.58.0",
         "@sveltejs/vite-plugin-svelte": "^7.0.0",
+        "@tailwindcss/vite": "^4.2.2",
         "@types/eslint": "^9.6.0",
         "@types/node": "^25.6.0",
-        "autoprefixer": "^10.5.0",
         "eslint": "^10.2.1",
         "eslint-config-prettier": "^10.1.8",
         "eslint-plugin-svelte": "^3.17.1",
@@ -31,7 +31,7 @@
         "prettier-plugin-svelte": "^3.5.1",
         "svelte": "^5.55.5",
         "svelte-check": "^4.4.6",
-        "tailwindcss": "^3.4.18",
+        "tailwindcss": "^4.2.2",
         "typescript": "^6.0.3",
         "typescript-eslint": "^8.59.0",
         "vite": "^8.0.10",