Replace preprocess-fixtures script with webpack plugin for automatic fixture copying

Co-authored-by: alexr00 <38270282+alexr00@users.noreply.github.com>

Author: Copilot

package.json

@@ -4172,14 +4172,14 @@
 	},
 	"scripts": {
 		"postinstall": "yarn update-dts",
-		"bundle": "webpack --mode production --env esbuild && node scripts/preprocess-fixtures --in src --out dist",
-		"bundle:node": "webpack --mode production --config-name extension:node --config-name webviews && node scripts/preprocess-fixtures --in src --out dist",
+		"bundle": "webpack --mode production --env esbuild",
+		"bundle:node": "webpack --mode production --config-name extension:node --config-name webviews",
 		"bundle:web": "webpack --mode production --config-name extension:webworker --config-name webviews",
 		"clean": "rm -r dist/",
-		"compile": "webpack --mode development --env esbuild && node scripts/preprocess-fixtures --in src --out dist",
+		"compile": "webpack --mode development --env esbuild",
 		"compile:test": "tsc -p tsconfig.test.json",
 		"watch:test": "tsc -w -p tsconfig.test.json",
-		"compile:node": "webpack --mode development --config-name extension:node --config-name webviews && node scripts/preprocess-fixtures --in src --out dist",
+		"compile:node": "webpack --mode development --config-name extension:node --config-name webviews",
 		"compile:web": "webpack --mode development --config-name extension:webworker --config-name webviews",
 		"lint": "eslint --fix --cache --config .eslintrc.js --ignore-pattern src/env/browser/**/* \"{src,webviews}/**/*.{ts,tsx}\"",
 		"lint:browser": "eslint --fix --cache --cache-location .eslintcache.browser --config .eslintrc.browser.json --ignore-pattern src/env/node/**/* \"{src,webviews}/**/*.{ts,tsx}\"",
@@ -4192,7 +4192,7 @@
 		"test:preprocess-svg": "node scripts/preprocess-svg --in ../resources/ --out out/resources",
 		"test:preprocess-fixtures": "node scripts/preprocess-fixtures --in src --out out",
 		"update-dts": "cd \"src/@types\" && npx vscode-dts main && npx vscode-dts dev",
-		"watch": "node scripts/preprocess-fixtures --in src --out dist && webpack --watch --mode development --env esbuild",
+		"watch": "webpack --watch --mode development --env esbuild",
 		"watch:web": "webpack --watch --mode development --config-name extension:webworker --config-name webviews",
 		"hygiene": "node ./build/hygiene.js",
 		"prepare": "husky install"

webpack.config.js

@@ -172,6 +172,43 @@ async function getExtensionConfig(target, mode, env) {
 		new webpack.ContextReplacementPlugin(/mocha/, /^$/)
 	];
 
+	// Add fixtures copying plugin for node target (which has individual test files)
+	if (target === 'node') {
+		const fs = require('fs');
+		
+		class CopyFixturesPlugin {
+			apply(compiler) {
+				compiler.hooks.afterEmit.tap('CopyFixturesPlugin', () => {
+					this.copyFixtures('src', compiler.options.output.path);
+				});
+			}
+			
+			copyFixtures(inputDir, outputDir) {
+				try {
+					const files = fs.readdirSync(inputDir);
+					for (const file of files) {
+						const filePath = path.join(inputDir, file);
+						const stats = fs.statSync(filePath);
+						if (stats.isDirectory()) {
+							if (file === 'fixtures') {
+								const outputFilePath = path.join(outputDir, inputDir, file);
+								const inputFilePath = path.join(inputDir, file);
+								fs.cpSync(inputFilePath, outputFilePath, { recursive: true, force: true });
+							} else {
+								this.copyFixtures(filePath, outputDir);
+							}
+						}
+					}
+				} catch (error) {
+					// Ignore errors during fixtures copying to not break the build
+					console.warn('Warning: Could not copy fixtures:', error.message);
+				}
+			}
+		}
+		
+		plugins.push(new CopyFixturesPlugin());
+	}
+
 	if (target === 'webworker') {
 		plugins.push(new webpack.ProvidePlugin({
 			process: path.join(