chore: upgrade Tailwind CSS to v4

- Replace @tailwind directives with @import "tailwindcss"
- Switch PostCSS plugin to @tailwindcss/postcss
- Add @theme inline block mapping CSS vars to v4 theme tokens
- Move accordion keyframes/animations to globals.css
- Remove tailwind.config.ts and tailwindcss-animate (no longer needed)
- Update components.json to clear config path

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

package.json

@@ -34,6 +34,7 @@
     "@radix-ui/react-switch": "^1.2.6",
     "@radix-ui/react-tabs": "^1.1.13",
     "@radix-ui/react-tooltip": "^1.2.8",
+    "@tailwindcss/postcss": "^4",
     "apexcharts": "^5.10.4",
     "autoprefixer": "^10.4.27",
     "bcryptjs": "^3.0.3",
@@ -59,7 +60,7 @@
     "react-map-gl": "^8.1.0",
     "sonner": "^2.0.7",
     "tailwind-merge": "^3.5.0",
-    "tailwindcss": "^3.4.19",
+    "tailwindcss": "^4",
     "topojson-client": "^3.1.0"
   },
   "devDependencies": {
@@ -79,7 +80,6 @@
     "drizzle-kit": "^0.31.10",
     "eslint": "^10.1.0",
     "shadcn": "^4.1.0",
-    "tailwindcss-animate": "^1.0.7",
     "typescript": "^5.9.3",
     "typescript-eslint": "^8.57.1",
     "vite-tsconfig-paths": "^6.1.1",