Add current time indicator to week view

- Add real-time current time indicator that updates every 5 seconds
- Display horizontal line with dot and time label on current day only
- Position indicator accurately based on time increment mode (15/30 min)
- Use theme-aware colors with subdued gray styling for dark mode
- Include subtle shadows and proper z-indexing for visibility

🤖 Generated with [Claude Code](https://claude.ai/code)

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

frontend/styles.css

@@ -1052,6 +1052,76 @@ body {
     background: linear-gradient(135deg, var(--event-color, #3B82F6), rgba(255,255,255,0.1)) !important;
 }
 
+/* Current Time Indicator */
+.current-time-indicator-container {
+    position: absolute;
+    top: 0;
+    left: 0;
+    right: 0;
+    bottom: 0;
+    pointer-events: none;
+    z-index: 20;
+}
+
+.current-time-indicator {
+    position: absolute;
+    left: 0;
+    right: 0;
+    height: 2px;
+    z-index: 20;
+    display: flex;
+    align-items: center;
+    pointer-events: none;
+}
+
+.current-time-dot {
+    width: 8px;
+    height: 8px;
+    border-radius: 50%;
+    background-color: var(--primary-color, #667eea);
+    position: absolute;
+    left: -4px;
+    z-index: 21;
+    flex-shrink: 0;
+}
+
+.current-time-line {
+    flex: 1;
+    height: 2px;
+    background-color: var(--primary-color, #667eea);
+    position: relative;
+}
+
+.current-time-label {
+    position: absolute;
+    right: -50px;
+    top: -10px;
+    background-color: var(--primary-color, #667eea);
+    color: white;
+    padding: 2px 6px;
+    border-radius: 4px;
+    font-size: 0.7rem;
+    font-weight: 600;
+    white-space: nowrap;
+    box-shadow: 0 2px 4px rgba(0,0,0,0.2);
+}
+
+/* Dark theme override for current time indicator */
+[data-theme="dark"] .current-time-dot {
+    background-color: #9ca3af;
+    box-shadow: 0 0 6px rgba(156, 163, 175, 0.4);
+}
+
+[data-theme="dark"] .current-time-line {
+    background-color: #9ca3af;
+    box-shadow: 0 1px 3px rgba(156, 163, 175, 0.3);
+}
+
+[data-theme="dark"] .current-time-label {
+    background-color: #6b7280;
+    box-shadow: 0 2px 8px rgba(107, 114, 128, 0.4);
+}
+
 /* Legacy Week Grid (for backward compatibility) */
 .week-grid {
     display: grid;