fix: watcher avatars, dependency TDS styling, asset versions, nav dropdown light theme

- watch_ticket.php GET now returns watcher list (up to 6 users) for avatar group
- TicketView: watcher avatar group rendered next to WATCH button, refreshes on toggle
- Rewrite renderDependencies/renderDependents to use TDS lt-kv-grid/lt-badge/lt-btn classes
- renderDependencies: show lt-alert--warning blocker banner when blocked_by has open tickets
- Fix ALL hardcoded ?v=20260327 asset version strings in CreateTicketView + all admin views
- base.css: fix .lt-nav-dropdown-menu hardcoded background → var(--bg-overlay)
- base.css: add light-theme overrides for nav dropdown menu (background, links, hover)
- ticket.css: add .lt-avatar-group and .lt-avatar--overflow styles for watcher display

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

api/watch_ticket.php

@@ -84,16 +84,28 @@ $watchingStmt->execute();
 $watching = (bool)$watchingStmt->get_result()->fetch_assoc()['cnt'];
 $watchingStmt->close();
 
-$countStmt = $conn->prepare(
-    "SELECT COUNT(*) as cnt FROM ticket_watchers WHERE ticket_id = ?"
+// Fetch watcher list (up to 6) with display names for avatar group
+$watchersStmt = $conn->prepare(
+    "SELECT u.user_id, COALESCE(u.display_name, u.username) AS display_name
+       FROM ticket_watchers tw
+       JOIN users u ON tw.user_id = u.user_id
+      WHERE tw.ticket_id = ?
+      ORDER BY tw.created_at ASC
+      LIMIT 6"
 );
-$countStmt->bind_param("i", $ticketId);
-$countStmt->execute();
-$count = (int)$countStmt->get_result()->fetch_assoc()['cnt'];
-$countStmt->close();
+$watchersStmt->bind_param("i", $ticketId);
+$watchersStmt->execute();
+$watchersResult = $watchersStmt->get_result();
+$watchers = [];
+while ($row = $watchersResult->fetch_assoc()) {
+    $watchers[] = ['user_id' => (int)$row['user_id'], 'display_name' => $row['display_name']];
+}
+$watchersStmt->close();
+$count = count($watchers);
 
 echo json_encode([
     'success'       => true,
     'watching'      => $watching,
     'watcher_count' => $count,
+    'watchers'      => $watchers,
 ]);