Add password authentication to WebUI and implement session management

- Updated WebUI configuration to include a password field for authentication.
- Enhanced the WebUI server to handle login and logout functionality with session management.
- Added tests for authentication and session handling.
- Updated README and example configuration to reflect new authentication features.

src/webui/static/style.css

@@ -18,11 +18,22 @@ body {
 }
 
 header {
-    text-align: center;
     margin-bottom: 40px;
     color: white;
 }
 
+.header-content {
+    display: flex;
+    justify-content: space-between;
+    align-items: center;
+    text-align: left;
+}
+
+.header-content > div:first-child {
+    text-align: center;
+    flex: 1;
+}
+
 header h1 {
     font-size: 2.5rem;
     margin-bottom: 10px;
@@ -34,6 +45,21 @@ header p {
     opacity: 0.9;
 }
 
+.logout-btn {
+    background: rgba(255, 255, 255, 0.2);
+    color: white;
+    border: 1px solid rgba(255, 255, 255, 0.3);
+    padding: 8px 16px;
+    border-radius: 6px;
+    cursor: pointer;
+    font-size: 14px;
+    transition: background 0.2s ease;
+}
+
+.logout-btn:hover {
+    background: rgba(255, 255, 255, 0.3);
+}
+
 main {
     background: white;
     border-radius: 12px;
@@ -122,6 +148,15 @@ footer {
         padding: 10px;
     }
     
+    .header-content {
+        flex-direction: column;
+        gap: 20px;
+    }
+    
+    .header-content > div:first-child {
+        text-align: center;
+    }
+    
     header h1 {
         font-size: 2rem;
     }