Add ticket tags system, tag filtering, and auto-close feature

- Fix tickets API endpoint: add type, customer_name, customer_id, tags fields
- Add tags array to ticket data structure with add/remove UI
- Add tag filter input to toolbar and tag column in ticket list
- Add ticket_tags API endpoint for updating tags
- Add set_tags and auto_close_days actions to auto-rules
- Auto-close check runs on ticket list load, closes expired tickets
- Add tag CSS styles with editable tag badges in detail view

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

style.css

@@ -1274,6 +1274,44 @@ span.empty {
     border-color: #0f3460;
 }
 
+/* Ticket tags */
+.ticket-tag {
+    display: inline-block;
+    padding: 2px 8px;
+    border-radius: 10px;
+    font-size: 0.72rem;
+    font-weight: 600;
+    background: #e8ebf0;
+    color: #555;
+    white-space: nowrap;
+    letter-spacing: 0.2px;
+}
+
+.ticket-tag-editable {
+    display: inline-flex;
+    align-items: center;
+    gap: 3px;
+    padding: 3px 6px 3px 8px;
+    cursor: default;
+}
+
+.ticket-tag-remove {
+    background: none;
+    border: none;
+    cursor: pointer;
+    font-size: 0.85rem;
+    color: #999;
+    padding: 0 2px;
+    line-height: 1;
+    border-radius: 3px;
+    transition: color 0.15s, background 0.15s;
+}
+
+.ticket-tag-remove:hover {
+    color: #e74c3c;
+    background: rgba(231, 76, 60, 0.1);
+}
+
 /* Changelog */
 .nowrap {
     white-space: nowrap;