Add frontend autoformatting and set CI to require formatted code for all languages (#6052)

# Description of Changes
Changes the strategy for autoformatting to reject PRs if they are not
formatted correctly instead of allowing them to merge and then spawning
a new PR to fix the formatting. The old strategy just caused more work
for us because we'd have to manually approve the followup PR and get it
merged, which required 2 reviewers so in practice it rarely got done and
just meant everyone's PRs ended up containing reformatting for unrelated
files, which makes code review unnecessarily difficult. If the PR's code
is not formatted correctly after this PR, a comment will be added
automatically to tell the author how to run the formatter script to fix
their code so it can go in.

This also enables autoformatting for the frontend code, using Prettier.
I've enabled it for pretty much everything in the frontend folder, other
than 3rd party files and files it doesn't make sense for. I also
excluded Markdown because it sounds likely to be more annoying to have
to autoformat the Markdown in the frontend folder but nowhere else. Open
to changing this though if people disagree.

> [!note]
> 
> Advice to reviewers: The first commit contains all of the actual logic
I've introduced (CI changes, Prettier config, etc.)
> The second commit is just the reformatting of the entire frontend
folder.
> The first commit needs proper review, the second one just give it a
spot-check that it's doing what you'd expect.

frontend/src/core/components/shared/FilePreview.tsx

@@ -1,26 +1,26 @@
-import React from 'react';
-import { Box, Center } from '@mantine/core';
-import InsertDriveFileIcon from '@mui/icons-material/InsertDriveFile';
-import { StirlingFileStub } from '@app/types/fileContext';
-import DocumentThumbnail from '@app/components/shared/filePreview/DocumentThumbnail';
-import DocumentStack from '@app/components/shared/filePreview/DocumentStack';
-import HoverOverlay from '@app/components/shared/filePreview/HoverOverlay';
-import NavigationArrows from '@app/components/shared/filePreview/NavigationArrows';
+import React from "react";
+import { Box, Center } from "@mantine/core";
+import InsertDriveFileIcon from "@mui/icons-material/InsertDriveFile";
+import { StirlingFileStub } from "@app/types/fileContext";
+import DocumentThumbnail from "@app/components/shared/filePreview/DocumentThumbnail";
+import DocumentStack from "@app/components/shared/filePreview/DocumentStack";
+import HoverOverlay from "@app/components/shared/filePreview/HoverOverlay";
+import NavigationArrows from "@app/components/shared/filePreview/NavigationArrows";
 
 export interface FilePreviewProps {
   // Core file data
   file: File | StirlingFileStub | null;
   thumbnail?: string | null;
-  
+
   // Optional features
   showStacking?: boolean;
   showHoverOverlay?: boolean;
   showNavigation?: boolean;
-  
+
   // State
   totalFiles?: number;
   isAnimating?: boolean;
-  
+
   // Event handlers
   onFileClick?: (file: File | StirlingFileStub | null) => void;
   onPrevious?: () => void;
@@ -37,41 +37,38 @@ const FilePreview: React.FC<FilePreviewProps> = ({
   isAnimating = false,
   onFileClick,
   onPrevious,
-  onNext
+  onNext,
 }) => {
   if (!file) {
     return (
-      <Box style={{ width: '100%', height: '100%' }}>
-        <Center style={{ width: '100%', height: '100%' }}>
-          <InsertDriveFileIcon 
-            style={{ 
-              fontSize: '4rem', 
-              color: 'var(--mantine-color-gray-4)',
-              opacity: 0.6 
-            }} 
+      <Box style={{ width: "100%", height: "100%" }}>
+        <Center style={{ width: "100%", height: "100%" }}>
+          <InsertDriveFileIcon
+            style={{
+              fontSize: "4rem",
+              color: "var(--mantine-color-gray-4)",
+              opacity: 0.6,
+            }}
           />
         </Center>
       </Box>
     );
   }
-  
+
   const hasMultipleFiles = totalFiles > 1;
-  
+
   // Animation styles
-  const animationStyle = isAnimating ? {
-    transition: 'all 0.3s cubic-bezier(0.4, 0, 0.2, 1)',
-    transform: 'scale(0.95) translateX(1.25rem)',
-    opacity: 0.7
-  } : {};
+  const animationStyle = isAnimating
+    ? {
+        transition: "all 0.3s cubic-bezier(0.4, 0, 0.2, 1)",
+        transform: "scale(0.95) translateX(1.25rem)",
+        opacity: 0.7,
+      }
+    : {};
 
   // Build the component composition
   let content = (
-    <DocumentThumbnail
-      file={file}
-      thumbnail={thumbnail}
-      style={animationStyle}
-      onClick={() => onFileClick?.(file)}
-    />
+    <DocumentThumbnail file={file} thumbnail={thumbnail} style={animationStyle} onClick={() => onFileClick?.(file)} />
   );
 
   // Wrap with hover overlay if needed
@@ -81,31 +78,19 @@ const FilePreview: React.FC<FilePreviewProps> = ({
 
   // Wrap with document stack if needed
   if (showStacking) {
-    content = (
-      <DocumentStack totalFiles={totalFiles}>
-        {content}
-      </DocumentStack>
-    );
+    content = <DocumentStack totalFiles={totalFiles}>{content}</DocumentStack>;
   }
 
   // Wrap with navigation if needed
   if (showNavigation && hasMultipleFiles && onPrevious && onNext) {
     content = (
-      <NavigationArrows
-        onPrevious={onPrevious}
-        onNext={onNext}
-        disabled={isAnimating}
-      >
+      <NavigationArrows onPrevious={onPrevious} onNext={onNext} disabled={isAnimating}>
         {content}
       </NavigationArrows>
     );
   }
 
-  return (
-    <Box style={{ width: '100%', height: '100%' }}>
-      {content}
-    </Box>
-  );
+  return <Box style={{ width: "100%", height: "100%" }}>{content}</Box>;
 };
 
-export default FilePreview;
+export default FilePreview;