Refactor load testing scripts to support Bash and PowerShell

- Updated README.md to reflect changes in load testing commands and added usage examples for Bash scripts.
- Converted PowerShell load testing scripts to Bash equivalents for better cross-platform compatibility.
- Added new Bash scripts: run-loadtests.sh, summarize-artillery.sh, and summarize-k6.sh to mirror existing PowerShell functionality.
- Updated admin-api.js and ws-chat.yml for consistency and improved performance metrics reporting.
- Enhanced error handling and output formatting in summary scripts for better readability.

frontend/vitest.config.ts

@@ -1,20 +1,20 @@
-import { defineConfig } from "vitest/config";
-
-export default defineConfig({
-  test: {
-    environment: "jsdom",
-    include: ["src/**/*.test.ts"],
-    coverage: {
-      provider: "v8",
-      reporter: ["text", "text-summary"],
-      include: ["src/**/*.ts"],
-      exclude: ["src/**/*.test.ts"],
-      thresholds: {
-        statements: 20,
-        branches: 15,
-        functions: 15,
-        lines: 20,
-      },
-    },
-  },
-});
+import { defineConfig } from "vitest/config";
+
+export default defineConfig({
+  test: {
+    environment: "jsdom",
+    include: ["src/**/*.test.ts"],
+    coverage: {
+      provider: "v8",
+      reporter: ["text", "text-summary"],
+      include: ["src/**/*.ts"],
+      exclude: ["src/**/*.test.ts"],
+      thresholds: {
+        statements: 20,
+        branches: 15,
+        functions: 15,
+        lines: 20,
+      },
+    },
+  },
+});