fix: search palette triggers highlight, restore CSS keyframe blink

- SearchPalette now calls requestHighlight(id) before goto()
- Restore smooth CSS @keyframes cardHighlight (0%→none, 25%→glow,
  75%→glow, 100%→none) instead of JS interval pulse
- Inline style.animation overrides class-based stagger animation;
  cleanup sets animation:'none' (inline beats class, no stagger replay)

frontend/src/app.css

@@ -184,7 +184,13 @@ a:focus-visible {
 	font-family: var(--font-mono);
 }
 
-/* Card highlight dim overlay for cross-entity navigation */
+/* Card highlight for cross-entity navigation */
+@keyframes cardHighlight {
+	0%, 100% { box-shadow: none; }
+	25%, 75% { box-shadow: 0 0 0 3px var(--color-primary), 0 0 20px color-mix(in srgb, var(--color-primary) 30%, transparent); }
+}
+
+/* Dim overlay behind highlighted card */
 .nav-dim-overlay {
 	position: fixed;
 	inset: 0;