feat: implement authentication modal and update dashboard password handling

src/templates/static/css/dashboard.css

@@ -1168,6 +1168,139 @@ tbody {
     opacity: 1;
 }
 
+/* Auth Modal */
+.auth-modal {
+    position: fixed;
+    z-index: 1000;
+    left: 0;
+    top: 0;
+    width: 100%;
+    height: 100%;
+    background-color: rgba(0, 0, 0, 0.7);
+    display: flex;
+    align-items: center;
+    justify-content: center;
+    backdrop-filter: blur(4px);
+}
+.auth-modal-content {
+    background-color: #161b22;
+    border: 1px solid #30363d;
+    border-radius: 12px;
+    width: 400px;
+    max-width: 90vw;
+    box-shadow: 0 16px 48px rgba(0, 0, 0, 0.6);
+    animation: authModalIn 0.2s ease-out;
+}
+@keyframes authModalIn {
+    from { opacity: 0; transform: scale(0.95) translateY(-10px); }
+    to { opacity: 1; transform: scale(1) translateY(0); }
+}
+.auth-modal-header {
+    padding: 20px 24px 16px;
+    display: flex;
+    justify-content: space-between;
+    align-items: center;
+    border-bottom: 1px solid #30363d;
+}
+.auth-modal-title {
+    display: flex;
+    align-items: center;
+    gap: 10px;
+    color: #58a6ff;
+}
+.auth-modal-title h3 {
+    margin: 0;
+    font-size: 16px;
+    font-weight: 600;
+    color: #e6edf3;
+}
+.auth-modal-close {
+    color: #8b949e;
+    font-size: 24px;
+    font-weight: bold;
+    cursor: pointer;
+    line-height: 20px;
+    transition: color 0.2s;
+}
+.auth-modal-close:hover {
+    color: #c9d1d9;
+}
+.auth-modal-body {
+    padding: 24px;
+}
+.auth-modal-description {
+    margin: 0 0 20px;
+    color: #8b949e;
+    font-size: 14px;
+    line-height: 1.5;
+}
+.auth-modal-input-group {
+    margin-bottom: 20px;
+}
+.auth-modal-input {
+    width: 100%;
+    padding: 10px 14px;
+    background: #0d1117;
+    border: 1px solid #30363d;
+    border-radius: 6px;
+    color: #e6edf3;
+    font-size: 14px;
+    outline: none;
+    transition: border-color 0.2s, box-shadow 0.2s;
+    box-sizing: border-box;
+}
+.auth-modal-input:focus {
+    border-color: #58a6ff;
+    box-shadow: 0 0 0 3px rgba(88, 166, 255, 0.15);
+}
+.auth-modal-input-error {
+    border-color: #f85149;
+}
+.auth-modal-input-error:focus {
+    border-color: #f85149;
+    box-shadow: 0 0 0 3px rgba(248, 81, 73, 0.15);
+}
+.auth-modal-error {
+    margin: 8px 0 0;
+    color: #f85149;
+    font-size: 13px;
+}
+.auth-modal-footer {
+    display: flex;
+    justify-content: flex-end;
+    gap: 10px;
+}
+.auth-modal-btn {
+    padding: 8px 20px;
+    border-radius: 6px;
+    font-size: 14px;
+    font-weight: 500;
+    cursor: pointer;
+    border: 1px solid transparent;
+    transition: all 0.2s;
+}
+.auth-modal-btn-cancel {
+    background: transparent;
+    border-color: #30363d;
+    color: #8b949e;
+}
+.auth-modal-btn-cancel:hover {
+    background: #21262d;
+    color: #c9d1d9;
+}
+.auth-modal-btn-submit {
+    background: #238636;
+    color: #fff;
+    border-color: rgba(240, 246, 252, 0.1);
+}
+.auth-modal-btn-submit:hover {
+    background: #2ea043;
+}
+.auth-modal-btn-submit:disabled {
+    opacity: 0.6;
+    cursor: not-allowed;
+}
+
 /* Attack Types Cell Styling */
 .attack-types-cell {
     max-width: 280px;

src/templates/static/js/dashboard.js

@@ -22,6 +22,7 @@ document.addEventListener('alpine:init', () => {
 
         // Auth state (UI only — actual security enforced server-side via cookie)
         authenticated: false,
+        authModal: { show: false, password: '', error: '', loading: false },
 
         async init() {
             // Check if already authenticated (cookie-based)
@@ -97,24 +98,50 @@ document.addEventListener('alpine:init', () => {
             if (this.tab === 'admin') this.switchToOverview();
         },
 
-        async promptAuth() {
-            const password = prompt('Enter dashboard password:');
-            if (!password) return;
+        promptAuth() {
+            this.authModal = { show: true, password: '', error: '', loading: false };
+            this.$nextTick(() => {
+                if (this.$refs.authPasswordInput) this.$refs.authPasswordInput.focus();
+            });
+        },
+
+        closeAuthModal() {
+            this.authModal.show = false;
+            this.authModal.password = '';
+            this.authModal.error = '';
+            this.authModal.loading = false;
+        },
+
+        async submitAuth() {
+            const password = this.authModal.password;
+            if (!password) {
+                this.authModal.error = 'Please enter a password';
+                return;
+            }
+            this.authModal.error = '';
+            this.authModal.loading = true;
             try {
+                const msgBuf = new TextEncoder().encode(password);
+                const hashBuf = await crypto.subtle.digest('SHA-256', msgBuf);
+                const fingerprint = Array.from(new Uint8Array(hashBuf))
+                    .map(b => b.toString(16).padStart(2, '0')).join('');
                 const resp = await fetch(`${this.dashboardPath}/api/auth`, {
                     method: 'POST',
                     headers: { 'Content-Type': 'application/json' },
                     credentials: 'same-origin',
-                    body: JSON.stringify({ password }),
+                    body: JSON.stringify({ fingerprint }),
                 });
                 if (resp.ok) {
                     this.authenticated = true;
+                    this.closeAuthModal();
                     this.switchToAdmin();
                 } else {
-                    alert('Invalid password');
+                    this.authModal.error = 'Invalid password';
+                    this.authModal.loading = false;
                 }
             } catch {
-                alert('Authentication failed');
+                this.authModal.error = 'Authentication failed';
+                this.authModal.loading = false;
             }
         },