build: update npm install command to use --legacy-peer-deps

This change modifies the build scripts to use --legacy-peer-deps flag when installing npm dependencies to resolve potential peer dependency conflicts during the build process. The change is applied to both bash (build.sh) and batch (build.bat) build scripts.

frontend/node_modules/eslint/lib/cli-engine/formatters/checkstyle.js

@@ -0,0 +1,60 @@
+/**
+ * @fileoverview CheckStyle XML reporter
+ * @author Ian Christian Myers
+ */
+"use strict";
+
+const xmlEscape = require("../xml-escape");
+
+//------------------------------------------------------------------------------
+// Helper Functions
+//------------------------------------------------------------------------------
+
+/**
+ * Returns the severity of warning or error
+ * @param {Object} message message object to examine
+ * @returns {string} severity level
+ * @private
+ */
+function getMessageType(message) {
+    if (message.fatal || message.severity === 2) {
+        return "error";
+    }
+    return "warning";
+
+}
+
+//------------------------------------------------------------------------------
+// Public Interface
+//------------------------------------------------------------------------------
+
+module.exports = function(results) {
+
+    let output = "";
+
+    output += "<?xml version=\"1.0\" encoding=\"utf-8\"?>";
+    output += "<checkstyle version=\"4.3\">";
+
+    results.forEach(result => {
+        const messages = result.messages;
+
+        output += `<file name="${xmlEscape(result.filePath)}">`;
+
+        messages.forEach(message => {
+            output += [
+                `<error line="${xmlEscape(message.line || 0)}"`,
+                `column="${xmlEscape(message.column || 0)}"`,
+                `severity="${xmlEscape(getMessageType(message))}"`,
+                `message="${xmlEscape(message.message)}${message.ruleId ? ` (${message.ruleId})` : ""}"`,
+                `source="${message.ruleId ? xmlEscape(`eslint.rules.${message.ruleId}`) : ""}" />`
+            ].join(" ");
+        });
+
+        output += "</file>";
+
+    });
+
+    output += "</checkstyle>";
+
+    return output;
+};