feat: Add user edit modal and user management pages

- Implemented user edit modal in user_edit.html for editing user details.
- Updated sidebar.html to correctly reflect active states for Users and Settings.
- Created table-07.html for displaying user data in a structured format.
- Added settings.html for managing email content and configurations.
- Developed users.html for listing all users with functionality to add and edit users.

api/users/list.php

@@ -0,0 +1,34 @@
+<?php
+require "../api.php";
+
+$api = new spamhasiApi();
+
+if (!$api->checkAuth()) {
+    die('{"status":500, "error":"Unauthorized"}');
+}
+
+$db = $api->getDB();
+
+$sql = "SELECT * FROM users";
+$stmt = $db->query($sql);
+$result = $stmt->fetchAll(PDO::FETCH_ASSOC);
+
+$all_users = [];
+
+if ($result) {
+    foreach ($result as $user_res) {
+        $user["id"] = $user_res["id"];
+        $user["name"] = $user_res["username"];
+
+        $all_users[] = $user;
+    }
+
+    $json["users"] = $all_users;
+}else{
+    $json["users"] = [];
+}
+
+$json["status"] = 200;
+
+die(json_encode($json));
+?>