Create a frontend wireframe. (#7)

Sets up API methods and types.
Sets up a colorscheme.
Sets up a homepage.

Removes tailwind in favor of mui for now.

Reviewed-on: #7
Co-authored-by: Drew Galbraith <drew@tiramisu.one>
Co-committed-by: Drew Galbraith <drew@tiramisu.one>

frontend/app/components/LoadingSpinner.tsx

@@ -0,0 +1,53 @@
+import React from 'react'
+import { Box, CircularProgress, Typography, Skeleton } from '@mui/material'
+
+interface LoadingSpinnerProps {
+  size?: number
+  message?: string
+  variant?: 'spinner' | 'skeleton'
+}
+
+export default function LoadingSpinner({
+  size = 40,
+  message = 'Loading...',
+  variant = 'spinner',
+}: LoadingSpinnerProps) {
+  if (variant === 'skeleton') {
+    return (
+      <Box sx={{ p: 2 }}>
+        <Skeleton variant="text" width="60%" height={32} sx={{ mb: 2 }} />
+        <Skeleton
+          variant="rectangular"
+          width="100%"
+          height={120}
+          sx={{ mb: 1 }}
+        />
+        <Skeleton
+          variant="rectangular"
+          width="100%"
+          height={120}
+          sx={{ mb: 1 }}
+        />
+        <Skeleton variant="rectangular" width="100%" height={120} />
+      </Box>
+    )
+  }
+
+  return (
+    <Box
+      sx={{
+        display: 'flex',
+        flexDirection: 'column',
+        alignItems: 'center',
+        justifyContent: 'center',
+        p: 4,
+        gap: 2,
+      }}
+    >
+      <CircularProgress size={size} thickness={4} />
+      <Typography variant="body2" color="text.secondary">
+        {message}
+      </Typography>
+    </Box>
+  )
+}