feat: saved filter pills, mention autocomplete CSS, tooltips on dashboard table

- Dashboard: saved filter pills row above active filters bar — loads from API,
  click applies criteria as URL params, hidden when no saved filters exist
- ticket.css: add TDS-styled CSS for @mention autocomplete dropdown (was unstyled)
- Dashboard table: data-tooltip on Title and Assigned To columns for truncated text
  (lt.tooltip.init() auto-called by lt.init(), zero extra JS needed)

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

assets/css/ticket.css

@@ -270,6 +270,42 @@ kbd {
   .thread-depth-3 { margin-left: 2.25rem; }
 }
 
+/* ── @mention autocomplete dropdown ─────────────────────────── */
+.mention-autocomplete {
+  display: none;
+  position: absolute;
+  z-index: 200;
+  background: var(--bg-overlay, #060c14);
+  border: 1px solid var(--accent-cyan-border, rgba(0,212,255,0.3));
+  box-shadow: 0 8px 24px rgba(0,0,0,0.6);
+  min-width: 200px;
+  max-width: 320px;
+}
+.mention-autocomplete.active { display: block; }
+.mention-option {
+  display: flex;
+  align-items: baseline;
+  gap: 0.5rem;
+  padding: 0.4rem 0.75rem;
+  cursor: pointer;
+  border-bottom: 1px solid var(--border-dim, rgba(0,255,65,0.1));
+  transition: background 0.1s;
+}
+.mention-option:last-child { border-bottom: none; }
+.mention-option.selected,
+.mention-option:hover {
+  background: rgba(0,212,255,0.08);
+}
+.mention-username {
+  font-size: 0.75rem;
+  font-weight: 700;
+  color: var(--accent-cyan, #00d4ff);
+}
+.mention-displayname {
+  font-size: 0.7rem;
+  color: var(--text-muted);
+}
+
 /* ── Watcher avatar group in toolbar ────────────────────────── */
 .lt-avatar-group {
   display: flex;