chore(#2): Standardize eslint, prettier, and vscode lint settings

.prettierrc

@@ -3,7 +3,7 @@
 	"singleQuote": true,
 	"trailingComma": "none",
 	"printWidth": 100,
-	"plugins": ["prettier-plugin-svelte", "prettier-plugin-tailwindcss"],
+	"plugins": ["prettier-plugin-tailwindcss", "prettier-plugin-svelte"],
 	"overrides": [
 		{
 			"files": "*.svelte",

.vscode/settings.json

@@ -0,0 +1,9 @@
+{
+	"editor.formatOnSave": true,
+	"editor.defaultFormatter": "esbenp.prettier-vscode",
+	"editor.codeActionsOnSave": {
+		"source.fixAll.eslint": "always"
+	},
+	"eslint.useFlatConfig": true,
+	"eslint.validate": ["javascript", "typescript", "svelte"]
+}

eslint.config.js

@@ -1,37 +1,89 @@
-import prettier from 'eslint-config-prettier';
-import js from '@eslint/js';
 import { includeIgnoreFile } from '@eslint/compat';
+import { FlatCompat } from '@eslint/eslintrc';
+import js from '@eslint/js';
+import prettier from 'eslint-config-prettier';
+import importPlugin from 'eslint-plugin-import';
 import svelte from 'eslint-plugin-svelte';
 import globals from 'globals';
+import path from 'node:path';
 import { fileURLToPath } from 'node:url';
-import ts from 'typescript-eslint';
+import tseslint from 'typescript-eslint';
 import svelteConfig from './svelte.config.js';
 
 const gitignorePath = fileURLToPath(new URL('./.gitignore', import.meta.url));
+const baseDirectory = path.dirname(fileURLToPath(import.meta.url));
+const compat = new FlatCompat({
+	baseDirectory,
+	recommendedConfig: js.configs.recommended
+});
 
-export default ts.config(
+const airbnbBaseConfig = compat.extends('airbnb-base').map((config) => ({
+	...config,
+	files: ['**/*.{js,cjs,mjs,ts,cts,mts}']
+}));
+
+export default tseslint.config(
 	includeIgnoreFile(gitignorePath),
-	js.configs.recommended,
-	...ts.configs.recommended,
-	...svelte.configs.recommended,
+	{
+		ignores: ['eslint.config.js', 'svelte.config.js', 'vite.config.ts']
+	},
+	{
+		plugins: {
+			import: importPlugin
+		}
+	},
+	...airbnbBaseConfig,
+	...tseslint.configs.recommended,
+	...svelte.configs['flat/recommended'],
 	prettier,
-	...svelte.configs.prettier,
+	...svelte.configs['flat/prettier'],
 	{
 		languageOptions: {
 			globals: { ...globals.browser, ...globals.node }
 		},
-		rules: { 'no-undef': 'off' }
+		settings: {
+			'import/resolver': {
+				node: {
+					extensions: ['.js', '.mjs', '.cjs', '.ts', '.d.ts', '.svelte', '.json']
+				}
+			},
+			'import/extensions': ['.js', '.ts', '.mjs', '.svelte']
+		},
+		rules: {
+			curly: ['error', 'all'],
+			'brace-style': ['error', '1tbs', { allowSingleLine: false }],
+			'no-continue': 'off',
+			'no-restricted-syntax': 'off',
+			'no-inner-declarations': 'off',
+			'no-unused-vars': 'off',
+			'import/no-extraneous-dependencies': 'off',
+			'@typescript-eslint/no-unused-vars': ['warn', { argsIgnorePattern: '^_' }],
+			'import/extensions': [
+				'error',
+				'ignorePackages',
+				{
+					js: 'never',
+					mjs: 'never',
+					cjs: 'never',
+					ts: 'never'
+				}
+			]
+		}
 	},
 	{
 		files: ['**/*.svelte', '**/*.svelte.ts', '**/*.svelte.js'],
-		ignores: ['eslint.config.js', 'svelte.config.js'],
 		languageOptions: {
 			parserOptions: {
 				projectService: true,
 				extraFileExtensions: ['.svelte'],
-				parser: ts.parser,
+				parser: tseslint.parser,
 				svelteConfig
 			}
+		},
+		rules: {
+			// Svelte components commonly export mutable props and top-level declarations.
+			'import/prefer-default-export': 'off',
+			'import/no-mutable-exports': 'off'
 		}
 	}
 );