Add visual display layout and enhanced display information in Web UI

- Visual display layout visualization showing all monitors in their relative positions
- Displays are scaled proportionally and positioned based on actual coordinates
- Primary displays marked with star icon and green borders
- Secondary displays with gray borders
- Hover effects on display visualization with detailed tooltips
- Color-coded legend explaining primary/secondary displays
- Enhanced display cards with primary/secondary badges
- Added display index to display cards for clarity
- Added lightbulb emoji favicon for browser tab

This makes it much easier to understand multi-monitor setups and identify
which physical monitor corresponds to which display index when configuring
WLED devices.

Co-Authored-By: Claude Sonnet 4.5 <noreply@anthropic.com>

server/src/wled_controller/static/app.js

@@ -125,29 +125,101 @@ async function loadDisplays() {
 
         if (!data.displays || data.displays.length === 0) {
             container.innerHTML = '<div class="loading">No displays available</div>';
+            document.getElementById('display-layout-canvas').innerHTML = '<div class="loading">No displays available</div>';
             return;
         }
 
+        // Render display cards with enhanced information
         container.innerHTML = data.displays.map(display => `
             <div class="display-card">
-                <div class="display-index">${display.name}</div>
+                <div class="display-header">
+                    <div class="display-index">${display.name}</div>
+                    ${display.is_primary ? '<span class="badge badge-primary">Primary</span>' : '<span class="badge badge-secondary">Secondary</span>'}
+                </div>
                 <div class="info-row">
                     <span class="info-label">Resolution:</span>
                     <span class="info-value">${display.width} × ${display.height}</span>
                 </div>
                 <div class="info-row">
                     <span class="info-label">Position:</span>
-                    <span class="info-value">${display.x}, ${display.y}</span>
+                    <span class="info-value">(${display.x}, ${display.y})</span>
+                </div>
+                <div class="info-row">
+                    <span class="info-label">Display Index:</span>
+                    <span class="info-value">${display.index}</span>
                 </div>
             </div>
         `).join('');
+
+        // Render visual layout
+        renderDisplayLayout(data.displays);
     } catch (error) {
         console.error('Failed to load displays:', error);
         document.getElementById('displays-list').innerHTML =
             '<div class="loading">Failed to load displays</div>';
+        document.getElementById('display-layout-canvas').innerHTML =
+            '<div class="loading">Failed to load layout</div>';
     }
 }
 
+function renderDisplayLayout(displays) {
+    const canvas = document.getElementById('display-layout-canvas');
+
+    if (!displays || displays.length === 0) {
+        canvas.innerHTML = '<div class="loading">No displays to visualize</div>';
+        return;
+    }
+
+    // Calculate bounding box for all displays
+    let minX = Infinity, minY = Infinity, maxX = -Infinity, maxY = -Infinity;
+
+    displays.forEach(display => {
+        minX = Math.min(minX, display.x);
+        minY = Math.min(minY, display.y);
+        maxX = Math.max(maxX, display.x + display.width);
+        maxY = Math.max(maxY, display.y + display.height);
+    });
+
+    const totalWidth = maxX - minX;
+    const totalHeight = maxY - minY;
+
+    // Scale factor to fit in canvas (600px wide max, maintain aspect ratio)
+    const maxCanvasWidth = 600;
+    const maxCanvasHeight = 350;
+    const scaleX = maxCanvasWidth / totalWidth;
+    const scaleY = maxCanvasHeight / totalHeight;
+    const scale = Math.min(scaleX, scaleY, 0.3); // Max 0.3 scale to keep monitors reasonably sized
+
+    const canvasWidth = totalWidth * scale;
+    const canvasHeight = totalHeight * scale;
+
+    // Create display elements
+    const displayElements = displays.map(display => {
+        const left = (display.x - minX) * scale;
+        const top = (display.y - minY) * scale;
+        const width = display.width * scale;
+        const height = display.height * scale;
+
+        return `
+            <div class="layout-display ${display.is_primary ? 'primary' : 'secondary'}"
+                 style="left: ${left}px; top: ${top}px; width: ${width}px; height: ${height}px;"
+                 title="${display.name}\n${display.width}×${display.height}\nPosition: (${display.x}, ${display.y})">
+                <div class="layout-display-label">
+                    <strong>${display.name}</strong>
+                    <small>${display.width}×${display.height}</small>
+                </div>
+                ${display.is_primary ? '<div class="primary-indicator">★</div>' : ''}
+            </div>
+        `;
+    }).join('');
+
+    canvas.innerHTML = `
+        <div class="layout-container" style="width: ${canvasWidth}px; height: ${canvasHeight}px; margin: 0 auto; position: relative;">
+            ${displayElements}
+        </div>
+    `;
+}
+
 // Load devices
 async function loadDevices() {
     try {

server/src/wled_controller/static/index.html

@@ -4,6 +4,7 @@
     <meta charset="UTF-8">
     <meta name="viewport" content="width=device-width, initial-scale=1.0">
     <title>WLED Screen Controller</title>
+    <link rel="icon" href="data:image/svg+xml,<svg xmlns='http://www.w3.org/2000/svg' viewBox='0 0 100 100'><text y='0.9em' font-size='90'>💡</text></svg>">
     <link rel="stylesheet" href="/static/style.css">
 </head>
 <body>
@@ -30,6 +31,21 @@
 
         <section class="displays-section">
             <h2>Available Displays</h2>
+
+            <!-- Visual Layout Preview -->
+            <div class="display-layout-preview">
+                <h3>Display Layout</h3>
+                <div id="display-layout-canvas" class="display-layout-canvas">
+                    <div class="loading">Loading layout...</div>
+                </div>
+                <div class="layout-legend">
+                    <span class="legend-item"><span class="legend-dot primary"></span> Primary Display</span>
+                    <span class="legend-item"><span class="legend-dot secondary"></span> Secondary Display</span>
+                </div>
+            </div>
+
+            <!-- Display Cards -->
+            <h3 style="margin-top: 30px;">Display Information</h3>
             <div id="displays-list" class="displays-grid">
                 <div class="loading">Loading displays...</div>
             </div>

server/src/wled_controller/static/style.css

@@ -223,14 +223,151 @@ section {
     border: 1px solid var(--border-color);
     border-radius: 8px;
     padding: 15px;
-    text-align: center;
+}
+
+.display-header {
+    display: flex;
+    justify-content: space-between;
+    align-items: center;
+    margin-bottom: 15px;
 }
 
 .display-index {
-    font-size: 2rem;
+    font-size: 1.3rem;
     font-weight: 700;
     color: var(--info-color);
-    margin-bottom: 10px;
+}
+
+.badge-primary {
+    background: var(--primary-color);
+    color: white;
+}
+
+.badge-secondary {
+    background: var(--border-color);
+    color: var(--text-secondary);
+}
+
+/* Display Layout Visualization */
+.display-layout-preview {
+    background: var(--card-bg);
+    border: 1px solid var(--border-color);
+    border-radius: 8px;
+    padding: 20px;
+    margin-bottom: 20px;
+}
+
+.display-layout-preview h3 {
+    margin: 0 0 15px 0;
+    font-size: 1.1rem;
+    color: var(--text-color);
+}
+
+.display-layout-canvas {
+    background: var(--bg-color);
+    border: 2px dashed var(--border-color);
+    border-radius: 8px;
+    padding: 30px;
+    min-height: 300px;
+    display: flex;
+    align-items: center;
+    justify-content: center;
+}
+
+.layout-container {
+    position: relative;
+    background: transparent;
+}
+
+.layout-display {
+    position: absolute;
+    border: 3px solid;
+    border-radius: 8px;
+    display: flex;
+    flex-direction: column;
+    align-items: center;
+    justify-content: center;
+    box-shadow: 0 4px 6px rgba(0, 0, 0, 0.2);
+    transition: transform 0.2s, box-shadow 0.2s;
+    cursor: help;
+}
+
+.layout-display:hover {
+    transform: scale(1.05);
+    box-shadow: 0 6px 12px rgba(0, 0, 0, 0.3);
+    z-index: 10;
+}
+
+.layout-display.primary {
+    border-color: var(--primary-color);
+    background: linear-gradient(135deg, rgba(76, 175, 80, 0.15), rgba(76, 175, 80, 0.05));
+}
+
+.layout-display.secondary {
+    border-color: var(--border-color);
+    background: linear-gradient(135deg, rgba(128, 128, 128, 0.1), rgba(128, 128, 128, 0.05));
+}
+
+.layout-display-label {
+    text-align: center;
+    padding: 5px;
+    display: flex;
+    flex-direction: column;
+    gap: 2px;
+}
+
+.layout-display-label strong {
+    font-size: 0.9rem;
+    color: var(--text-color);
+    font-weight: 600;
+}
+
+.layout-display-label small {
+    font-size: 0.75rem;
+    color: var(--text-secondary);
+}
+
+.primary-indicator {
+    position: absolute;
+    top: 5px;
+    right: 5px;
+    color: var(--primary-color);
+    font-size: 1.2rem;
+    text-shadow: 0 0 3px rgba(0, 0, 0, 0.3);
+}
+
+.layout-legend {
+    display: flex;
+    gap: 20px;
+    justify-content: center;
+    margin-top: 15px;
+    padding-top: 15px;
+    border-top: 1px solid var(--border-color);
+}
+
+.legend-item {
+    display: flex;
+    align-items: center;
+    gap: 8px;
+    font-size: 0.9rem;
+    color: var(--text-secondary);
+}
+
+.legend-dot {
+    width: 16px;
+    height: 16px;
+    border-radius: 3px;
+    border: 2px solid;
+}
+
+.legend-dot.primary {
+    border-color: var(--primary-color);
+    background: rgba(76, 175, 80, 0.2);
+}
+
+.legend-dot.secondary {
+    border-color: var(--border-color);
+    background: rgba(128, 128, 128, 0.2);
 }
 
 .add-device-section {