feat: add Panda CSS styling system with fonts and icons

Add @pandacss/dev, srjuggernaut-panda-preset, FontAwesome icons, and fonts to enable styling.
Update .gitignore to exclude styled-system directories.

postcss.config.ts

@@ -0,0 +1,6 @@
+import pandacssPlugin from '@pandacss/dev/postcss'
+import type { Plugin, Processor, Transformer } from 'postcss'
+
+export default {
+  plugins: [pandacssPlugin()]
+} as { plugins: (Plugin | Transformer | Processor)[] }