Fix DHCP client unable to get IP and config not persisting

- Fixed verifyAssignment being too strict for new clients
- Fixed parseRequestedIP string conversion bug
- Fixed response sent to 0.0.0.0 instead of broadcast address
- Added SO_BROADCAST support for UDP socket
- Fixed session persistence after page refresh (localStorage)
- Added in-memory session store for auth middleware
- Added config reloader so DHCP server picks up web UI changes dynamically

web/static/css/style.css

@@ -0,0 +1,303 @@
+* {
+    margin: 0;
+    padding: 0;
+    box-sizing: border-box;
+}
+
+body {
+    font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, sans-serif;
+    background: #f5f5f5;
+    color: #333;
+}
+
+.container {
+    max-width: 1200px;
+    margin: 0 auto;
+    padding: 20px;
+}
+
+header {
+    background: #2c3e50;
+    color: white;
+    padding: 20px;
+    margin-bottom: 20px;
+    border-radius: 8px;
+}
+
+header h1 {
+    margin-bottom: 15px;
+}
+
+nav {
+    display: flex;
+    gap: 15px;
+    flex-wrap: wrap;
+}
+
+nav a {
+    color: white;
+    text-decoration: none;
+    padding: 8px 16px;
+    border-radius: 4px;
+    background: rgba(255,255,255,0.1);
+}
+
+nav a:hover {
+    background: rgba(255,255,255,0.2);
+}
+
+section {
+    background: white;
+    padding: 20px;
+    margin-bottom: 20px;
+    border-radius: 8px;
+    box-shadow: 0 2px 4px rgba(0,0,0,0.1);
+}
+
+h2 {
+    margin-bottom: 20px;
+    color: #2c3e50;
+}
+
+h3 {
+    margin-bottom: 15px;
+    color: #34495e;
+}
+
+/* Login Form */
+#loginForm {
+    max-width: 400px;
+    display: flex;
+    flex-direction: column;
+    gap: 15px;
+}
+
+input, select {
+    padding: 10px;
+    border: 1px solid #ddd;
+    border-radius: 4px;
+    font-size: 14px;
+}
+
+button {
+    padding: 10px 20px;
+    background: #3498db;
+    color: white;
+    border: none;
+    border-radius: 4px;
+    cursor: pointer;
+    font-size: 14px;
+}
+
+button:hover {
+    background: #2980b9;
+}
+
+/* Stats */
+.stats {
+    display: grid;
+    grid-template-columns: repeat(auto-fit, minmax(200px, 1fr));
+    gap: 20px;
+}
+
+.stat-card {
+    background: #3498db;
+    color: white;
+    padding: 20px;
+    border-radius: 8px;
+    text-align: center;
+}
+
+.stat-card h3 {
+    color: white;
+    margin-bottom: 10px;
+    font-size: 14px;
+}
+
+.stat-card p {
+    font-size: 36px;
+    font-weight: bold;
+}
+
+/* Status Grid */
+.status-grid {
+    display: grid;
+    grid-template-columns: repeat(auto-fit, minmax(200px, 1fr));
+    gap: 15px;
+}
+
+.status-item {
+    padding: 15px;
+    background: #f8f9fa;
+    border-radius: 4px;
+}
+
+.status-label {
+    display: block;
+    font-size: 14px;
+    color: #666;
+    margin-bottom: 5px;
+}
+
+.status-value {
+    font-size: 18px;
+    font-weight: bold;
+    color: #27ae60;
+}
+
+/* Info Grid */
+.info-grid {
+    display: grid;
+    grid-template-columns: repeat(auto-fit, minmax(200px, 1fr));
+    gap: 15px;
+}
+
+.info-item {
+    padding: 15px;
+    background: #f8f9fa;
+    border-radius: 4px;
+}
+
+.info-label {
+    display: block;
+    font-size: 14px;
+    color: #666;
+    margin-bottom: 5px;
+}
+
+.info-value {
+    font-size: 18px;
+    font-weight: bold;
+    color: #2c3e50;
+}
+
+/* Tables */
+table {
+    width: 100%;
+    border-collapse: collapse;
+    margin-top: 15px;
+}
+
+th, td {
+    padding: 12px;
+    text-align: left;
+    border-bottom: 1px solid #ddd;
+}
+
+th {
+    background: #f8f9fa;
+    font-weight: 600;
+}
+
+tr:hover {
+    background: #f8f9fa;
+}
+
+/* Panels */
+.panel {
+    margin-bottom: 30px;
+}
+
+/* Form Styles */
+.form-row {
+    margin-bottom: 15px;
+}
+
+.form-row label {
+    display: block;
+    margin-bottom: 5px;
+    font-weight: 500;
+    color: #34495e;
+}
+
+.form-row input[type="text"],
+.form-row input[type="number"] {
+    width: 100%;
+}
+
+.form-row input[type="checkbox"] {
+    width: auto;
+    margin-right: 10px;
+}
+
+/* Utility */
+.hidden {
+    display: none;
+}
+
+/* Pool Stats */
+.pool-stats {
+    display: grid;
+    grid-template-columns: repeat(auto-fit, minmax(200px, 1fr));
+    gap: 15px;
+    margin-bottom: 15px;
+}
+
+.stat-item {
+    padding: 15px;
+    background: #f8f9fa;
+    border-radius: 4px;
+}
+
+.stat-label {
+    display: block;
+    font-size: 14px;
+    color: #666;
+    margin-bottom: 5px;
+}
+
+.stat-value {
+    font-size: 18px;
+    font-weight: bold;
+    color: #2c3e50;
+}
+
+/* Pool Bar */
+.pool-bar {
+    height: 24px;
+    background: #e9ecef;
+    border-radius: 12px;
+    overflow: hidden;
+    margin-top: 10px;
+}
+
+.pool-bar-fill {
+    height: 100%;
+    background: linear-gradient(90deg, #27ae60, #2ecc71);
+    border-radius: 12px;
+    transition: width 0.3s ease;
+    display: flex;
+    align-items: center;
+    justify-content: center;
+    color: white;
+    font-size: 12px;
+    font-weight: bold;
+    min-width: 30px;
+}
+
+/* Client Status */
+.status-active {
+    color: #27ae60;
+    font-weight: bold;
+}
+
+.status-expired {
+    color: #e74c3c;
+    font-weight: bold;
+}
+
+/* Responsive */
+@media (max-width: 768px) {
+    .stats {
+        grid-template-columns: 1fr;
+    }
+    
+    .status-grid,
+    .info-grid {
+        grid-template-columns: 1fr;
+    }
+    
+    nav {
+        flex-direction: column;
+    }
+}