Add UI enhancements and new features

Keyboard Navigation:
- Add J/K keys for Gmail-style ticket list navigation
- Add N key for new ticket, C for comment focus
- Add G then D for go to dashboard (vim-style)
- Add 1-4 number keys for quick status changes on ticket page
- Add Enter to open selected ticket
- Update keyboard help modal with all new shortcuts

Ticket Age Indicator:
- Show "Last activity: X days ago" on ticket view
- Visual warning (yellow pulse) for tickets idle >5 days
- Critical warning (red pulse) for tickets idle >10 days

Ticket Clone Feature:
- Add "Clone" button on ticket view
- Creates copy with [CLONE] prefix in title
- Preserves description, priority, category, type, visibility
- Automatically creates "relates_to" dependency to original

Active Filter Badges:
- Show visual badges above ticket table for active filters
- Click X on badge to remove individual filter
- "Clear All" button to reset all filters
- Color-coded by filter type (status, priority, search)

Visual Enhancements:
- Add keyboard-selected row highlighting for J/K navigation
- Smooth animations for filter badges

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

assets/css/ticket.css

@@ -329,6 +329,57 @@ textarea[data-field="description"]:not(:disabled)::after {
     color: var(--terminal-green);
 }
 
+/* Ticket Age Indicator */
+.ticket-age {
+    display: inline-flex;
+    align-items: center;
+    gap: 0.5rem;
+    padding: 0.35rem 0.75rem;
+    margin-top: 0.5rem;
+    font-family: var(--font-mono);
+    font-size: 0.85rem;
+    border-radius: 0;
+    border: 1px solid var(--terminal-green);
+    background: rgba(0, 255, 65, 0.05);
+}
+
+.ticket-age.age-normal {
+    color: var(--terminal-green);
+    border-color: var(--terminal-green);
+}
+
+.ticket-age.age-warning {
+    color: var(--terminal-amber);
+    border-color: var(--terminal-amber);
+    background: rgba(255, 176, 0, 0.1);
+    animation: pulse-warning 2s ease-in-out infinite;
+}
+
+.ticket-age.age-critical {
+    color: var(--priority-1);
+    border-color: var(--priority-1);
+    background: rgba(255, 77, 77, 0.15);
+    animation: pulse-critical 1s ease-in-out infinite;
+}
+
+@keyframes pulse-warning {
+    0%, 100% { box-shadow: 0 0 5px rgba(255, 176, 0, 0.3); }
+    50% { box-shadow: 0 0 15px rgba(255, 176, 0, 0.6); }
+}
+
+@keyframes pulse-critical {
+    0%, 100% { box-shadow: 0 0 5px rgba(255, 77, 77, 0.3); }
+    50% { box-shadow: 0 0 20px rgba(255, 77, 77, 0.8); }
+}
+
+.ticket-age .age-icon {
+    font-size: 1rem;
+}
+
+.ticket-age .age-text {
+    font-weight: 500;
+}
+
 .status-priority-group {
     display: flex;
     gap: 10px;