feat: add sqlstring and supports-color modules

- Introduced sqlstring module for SQL escape and formatting.
- Added supports-color module to detect terminal color support.
- Created dashboard and login views with Bootstrap styling.
- Implemented user schema in SQL with mock data for testing.

backend/node_modules/async/internal/once.js

@@ -0,0 +1,17 @@
+"use strict";
+
+Object.defineProperty(exports, "__esModule", {
+    value: true
+});
+exports.default = once;
+function once(fn) {
+    function wrapper(...args) {
+        if (fn === null) return;
+        var callFn = fn;
+        fn = null;
+        callFn.apply(this, args);
+    }
+    Object.assign(wrapper, fn);
+    return wrapper;
+}
+module.exports = exports.default;