v3.36.0: a deliberate "insert the next card" cue for batch runs

The waiting phase is the only moment the operator must act, so it now:
- shows a card-into-reader SVG animation in the status modal (inline
  SVG, CSS keyframes in src/style.css; reduced-motion users get the
  static card-above-the-slot picture);
- plays a short Web Audio chime once per card, edge-triggered in the
  2 s poll so it never repeats (the AudioContext is unlocked by the
  Start click);
- sets the tab title to "Insert next card" while the window is hidden;
- offers a speaker toggle next to the status (persisted as
  simple_ram_batch_sound, on by default).

The prebuilt style.css was rebuilt: it had gone stale and lacked
utilities the UI already used (bg-blue-50 on the batch notice,
inline-flex, mx-2, max-h-48, w-44, min-w-24).

1022 Python + 1062 frontend green; simple-v470.

frontend/src/style.css

@@ -4,4 +4,27 @@
 
 .dark .text-heading {
   color: #f1f5f9;
-}
+}
+/* RAM batch: the "insert the next card" cue (v3.36.0).
+   The card slides into the reader slot and back; the slot glows while the
+   run waits.  The static transform is the reduced-motion fallback: the card
+   rests above the slot. */
+.ram-insert-card {
+  transform: translateY(-14px);
+  animation: ram-insert 2.8s ease-in-out infinite;
+}
+@keyframes ram-insert {
+  0%, 12% { transform: translateY(-14px); }
+  45%, 55% { transform: translateY(10px); }
+  88%, 100% { transform: translateY(-14px); }
+}
+.ram-insert-glow {
+  animation: ram-insert-glow 1.4s ease-in-out infinite;
+}
+@keyframes ram-insert-glow {
+  0%, 100% { opacity: 0.35; }
+  50% { opacity: 0.95; }
+}
+@media (prefers-reduced-motion: reduce) {
+  .ram-insert-card, .ram-insert-glow { animation: none; }
+}