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/eslint.config.mjs

@@ -1,62 +1,52 @@
 // @ts-check
 
-import eslint from '@eslint/js';
-import globals from 'globals';
-import { defineConfig } from 'eslint/config';
-import tseslint from 'typescript-eslint';
+import eslint from "@eslint/js";
+import globals from "globals";
+import { defineConfig } from "eslint/config";
+import tseslint from "typescript-eslint";
 
-const srcGlobs = [
-  'src/**/*.{js,mjs,jsx,ts,tsx}',
-];
-const nodeGlobs = [
-  'scripts/**/*.{js,ts,mjs}',
-  '*.config.{js,ts,mjs}',
-];
+const srcGlobs = ["src/**/*.{js,mjs,jsx,ts,tsx}"];
+const nodeGlobs = ["scripts/**/*.{js,ts,mjs}", "*.config.{js,ts,mjs}"];
 
 const baseRestrictedImportPatterns = [
-  { regex: '^\\.', message: "Use @app/* imports instead of relative imports." },
-  { regex: '^src/', message: "Use @app/* imports instead of absolute src/ imports." },
+  { regex: "^\\.", message: "Use @app/* imports instead of relative imports." },
+  { regex: "^src/", message: "Use @app/* imports instead of absolute src/ imports." },
 ];
 
 export default defineConfig(
   {
     // Everything that contains 3rd party code that we don't want to lint
-    ignores: [
-      'dist',
-      'node_modules',
-      'public',
-      'src-tauri',
-    ],
+    ignores: ["dist", "node_modules", "public", "src-tauri"],
   },
   eslint.configs.recommended,
   tseslint.configs.recommended,
   {
     rules: {
-      'no-restricted-imports': [
-        'error',
+      "no-restricted-imports": [
+        "error",
         {
           patterns: baseRestrictedImportPatterns,
         },
       ],
-      '@typescript-eslint/no-empty-object-type': [
-        'error',
+      "@typescript-eslint/no-empty-object-type": [
+        "error",
         {
           // Allow empty extending interfaces because there's no real reason not to, and it makes it obvious where to put extra attributes in the future
-          allowInterfaces: 'with-single-extends',
+          allowInterfaces: "with-single-extends",
         },
       ],
-      '@typescript-eslint/no-explicit-any': 'off', // Temporarily disabled until codebase conformant
-      '@typescript-eslint/no-require-imports': 'off', // Temporarily disabled until codebase conformant
-      '@typescript-eslint/no-unused-vars': [
-        'error',
+      "@typescript-eslint/no-explicit-any": "off", // Temporarily disabled until codebase conformant
+      "@typescript-eslint/no-require-imports": "off", // Temporarily disabled until codebase conformant
+      "@typescript-eslint/no-unused-vars": [
+        "error",
         {
-          'args': 'all', // All function args must be used (or explicitly ignored)
-          'argsIgnorePattern': '^_', // Allow unused variables beginning with an underscore
-          'caughtErrors': 'all', // Caught errors must be used (or explicitly ignored)
-          'caughtErrorsIgnorePattern': '^_', // Allow unused variables beginning with an underscore
-          'destructuredArrayIgnorePattern': '^_', // Allow unused variables beginning with an underscore
-          'varsIgnorePattern': '^_', // Allow unused variables beginning with an underscore
-          'ignoreRestSiblings': true, // Allow unused variables when removing attributes from objects (otherwise this requires explicit renaming like `({ x: _x, ...y }) => y`, which is clunky)
+          args: "all", // All function args must be used (or explicitly ignored)
+          argsIgnorePattern: "^_", // Allow unused variables beginning with an underscore
+          caughtErrors: "all", // Caught errors must be used (or explicitly ignored)
+          caughtErrorsIgnorePattern: "^_", // Allow unused variables beginning with an underscore
+          destructuredArrayIgnorePattern: "^_", // Allow unused variables beginning with an underscore
+          varsIgnorePattern: "^_", // Allow unused variables beginning with an underscore
+          ignoreRestSiblings: true, // Allow unused variables when removing attributes from objects (otherwise this requires explicit renaming like `({ x: _x, ...y }) => y`, which is clunky)
         },
       ],
     },
@@ -65,15 +55,15 @@ export default defineConfig(
   // Use the stub/shadow pattern instead: define a stub in src/core/ and override in src/desktop/.
   {
     files: srcGlobs,
-    ignores: ['src/desktop/**'],
+    ignores: ["src/desktop/**"],
     rules: {
-      'no-restricted-imports': [
-        'error',
+      "no-restricted-imports": [
+        "error",
         {
           patterns: [
             ...baseRestrictedImportPatterns,
             {
-              regex: '^@tauri-apps/',
+              regex: "^@tauri-apps/",
               message: "Tauri APIs are desktop-only. Review frontend/DeveloperGuide.md for structure advice.",
             },
           ],
@@ -84,9 +74,9 @@ export default defineConfig(
   // Folders that have been cleaned up and are now conformant - stricter rules enforced here
   {
     files: [
-      'src/proprietary/**/*.{js,mjs,jsx,ts,tsx}',
-      'src/saas/**/*.{js,mjs,jsx,ts,tsx}',
-      'src/prototypes/**/*.{js,mjs,jsx,ts,tsx}',
+      "src/proprietary/**/*.{js,mjs,jsx,ts,tsx}",
+      "src/saas/**/*.{js,mjs,jsx,ts,tsx}",
+      "src/prototypes/**/*.{js,mjs,jsx,ts,tsx}",
     ],
     languageOptions: {
       parserOptions: {
@@ -95,8 +85,8 @@ export default defineConfig(
       },
     },
     rules: {
-      '@typescript-eslint/no-explicit-any': 'error',
-      '@typescript-eslint/no-unnecessary-type-assertion': 'error',
+      "@typescript-eslint/no-explicit-any": "error",
+      "@typescript-eslint/no-unnecessary-type-assertion": "error",
     },
   },
   // Config for browser scripts
@@ -105,8 +95,8 @@ export default defineConfig(
     languageOptions: {
       globals: {
         ...globals.browser,
-      }
-    }
+      },
+    },
   },
   // Config for node scripts
   {
@@ -114,7 +104,7 @@ export default defineConfig(
     languageOptions: {
       globals: {
         ...globals.node,
-      }
-    }
+      },
+    },
   },
 );