revert(live): animation honors VCR.speed in BOTH modes (restore #922)

Operator wants slow-mo / fast-anim available in LIVE as well as REPLAY.
The mode-gated divisor removed that. Restore original #922 behavior:
both stepMs and DURATION_MS divide by VCR.speed unconditionally, and
the speed button stays visible in LIVE so it can be adjusted.

Updates test assertions to match: LIVE @ 0.25× → 132ms, LIVE @ 4× → 8.25ms.

public/live.js

@@ -727,7 +727,10 @@
       if (pauseBtn) { pauseBtn.textContent = '⏸'; pauseBtn.setAttribute('aria-label', 'Pause'); }
       if (missedEl) missedEl.classList.add('hidden');
     }
-    if (speedBtn) { speedBtn.textContent = speedLabel(VCR.speed); speedBtn.setAttribute('aria-label', 'Speed ' + speedLabel(VCR.speed)); }
+    if (speedBtn) {
+      speedBtn.textContent = speedLabel(VCR.speed);
+      speedBtn.setAttribute('aria-label', 'Speed ' + speedLabel(VCR.speed));
+    }
     updateVCRLcd();
   }
 
@@ -3231,7 +3234,7 @@
 
     const matrixGreen = '#00ff41';
     const TRAIL_LEN = Math.min(6, bytes.length);
-    const DURATION_MS = 1100 / VCR.speed;
+    const DURATION_MS = 1100 / VCR.speed; // #922: animation honors VCR.speed
     const CHAR_INTERVAL = 0.06; // spawn a char every 6% of progress
     const charMarkers = [];
     let nextCharAt = CHAR_INTERVAL;
@@ -3363,7 +3366,7 @@
         return;
       }
       const elapsed = now - lastStep;
-      const stepMs = 33 / VCR.speed;
+      const stepMs = 33 / VCR.speed; // #922: animation honors VCR.speed
       if (elapsed >= stepMs) {
         const ticks = Math.min(Math.floor(elapsed / stepMs), 4);
         lastStep = now;

test-issue-1346-live-anim-speed.js

@@ -0,0 +1,106 @@
+/* Tests for #1346 — per-packet animation honors VCR.speed in BOTH modes.
+ *
+ * Bug history: PR #922 introduced `stepMs = 33 / VCR.speed` / `DURATION_MS = 1100 / VCR.speed`
+ * so slow-mo (0.25×) and fast-fwd (4×/8×) work for the per-packet animation. An interim fix
+ * mode-gated that to REPLAY only, which removed the ability to slow down / speed up LIVE
+ * animation. Operator wants the original #922 behavior restored: animation ALWAYS follows
+ * VCR.speed regardless of LIVE/REPLAY.
+ *
+ * Behavior:
+ *  - LIVE & REPLAY both → animation scaled by VCR.speed
+ *  - Inter-packet replay delay `realGap / VCR.speed` unchanged
+ *  - UI: speed button visible in BOTH modes (operator can adjust live-anim speed)
+ */
+'use strict';
+const fs = require('fs');
+const assert = require('assert');
+
+const src = fs.readFileSync('public/live.js', 'utf8');
+
+let passed = 0, failed = 0;
+function test(name, fn) {
+  try { fn(); passed++; console.log(`  ✅ ${name}`); }
+  catch (e) { failed++; console.log(`  ❌ ${name}: ${e.message}`); }
+}
+
+console.log('\n=== #1346 — per-packet animation honors VCR.speed in BOTH modes ===');
+
+function extractFn(name) {
+  const start = src.indexOf('function ' + name + '(');
+  assert.ok(start !== -1, `function ${name} not found`);
+  const next = src.indexOf('\n  function ', start + 1);
+  return src.substring(start, next === -1 ? start + 4000 : next);
+}
+
+function evalWithVCR(expr, VCR) {
+  return new Function('VCR', `return (${expr});`)(VCR);
+}
+
+// --- drawAnimatedLine.stepMs ---
+const stepExpr = extractFn('drawAnimatedLine').match(/const\s+stepMs\s*=\s*([^;]+);/)[1];
+
+test('LIVE @ speed=0.25 → stepMs = 132 (slow-mo works in LIVE too)', () => {
+  const v = evalWithVCR(stepExpr, { mode: 'LIVE', speed: 0.25 });
+  assert.strictEqual(v, 132, `got ${v}`);
+});
+test('LIVE @ speed=4 → stepMs = 8.25 (fast-anim works in LIVE too)', () => {
+  const v = evalWithVCR(stepExpr, { mode: 'LIVE', speed: 4 });
+  assert.strictEqual(v, 8.25, `got ${v}`);
+});
+test('LIVE @ speed=1 → stepMs = 33 (baseline)', () => {
+  const v = evalWithVCR(stepExpr, { mode: 'LIVE', speed: 1 });
+  assert.strictEqual(v, 33, `got ${v}`);
+});
+test('REPLAY @ speed=4 → stepMs = 8.25 (fast-forward animation)', () => {
+  const v = evalWithVCR(stepExpr, { mode: 'REPLAY', speed: 4 });
+  assert.strictEqual(v, 8.25, `got ${v}`);
+});
+test('REPLAY @ speed=0.25 → stepMs = 132 (#922 slow-mo preserved)', () => {
+  const v = evalWithVCR(stepExpr, { mode: 'REPLAY', speed: 0.25 });
+  assert.strictEqual(v, 132, `got ${v}`);
+});
+test('REPLAY @ speed=1 → stepMs = 33 (baseline)', () => {
+  const v = evalWithVCR(stepExpr, { mode: 'REPLAY', speed: 1 });
+  assert.strictEqual(v, 33, `got ${v}`);
+});
+
+// --- drawMatrixLine.DURATION_MS ---
+const durExpr = extractFn('drawMatrixLine').match(/const\s+DURATION_MS\s*=\s*([^;]+);/)[1];
+
+test('LIVE @ speed=4 → DURATION_MS = 275 (fast-fwd in LIVE)', () => {
+  const v = evalWithVCR(durExpr, { mode: 'LIVE', speed: 4 });
+  assert.strictEqual(v, 275, `got ${v}`);
+});
+test('LIVE @ speed=0.25 → DURATION_MS = 4400 (slow-mo in LIVE)', () => {
+  const v = evalWithVCR(durExpr, { mode: 'LIVE', speed: 0.25 });
+  assert.strictEqual(v, 4400, `got ${v}`);
+});
+test('REPLAY @ speed=4 → DURATION_MS = 275 (fast-forward)', () => {
+  const v = evalWithVCR(durExpr, { mode: 'REPLAY', speed: 4 });
+  assert.strictEqual(v, 275, `got ${v}`);
+});
+test('REPLAY @ speed=0.25 → DURATION_MS = 4400 (#922 slow-mo)', () => {
+  const v = evalWithVCR(durExpr, { mode: 'REPLAY', speed: 0.25 });
+  assert.strictEqual(v, 4400, `got ${v}`);
+});
+
+// --- inter-packet replay delay regression guard ---
+test('Inter-packet replay delay still divides realGap by VCR.speed', () => {
+  assert.ok(/delay\s*=\s*Math\.min\([^;]+?\/\s*VCR\.speed/.test(src),
+    'inter-packet replay delay must still divide realGap by VCR.speed');
+});
+
+// --- UI: speed button visible in BOTH modes ---
+test('updateVCRUI does NOT hide speed button in LIVE', () => {
+  const start = src.indexOf('function updateVCRUI(');
+  assert.ok(start !== -1, 'updateVCRUI not found');
+  const end = src.indexOf('\n  function ', start + 1);
+  const body = src.substring(start, end === -1 ? start + 4000 : end);
+  // No branch that adds 'hidden' class to speedBtn based on LIVE mode
+  assert.ok(!/speedBtn[\s\S]{0,200}VCR\.mode\s*===\s*['"]LIVE['"][\s\S]{0,200}classList\.add\(['"]hidden['"]\)/.test(body)
+         && !/VCR\.mode\s*===\s*['"]LIVE['"][\s\S]{0,200}speedBtn[\s\S]{0,200}classList\.add\(['"]hidden['"]\)/.test(body),
+    'speedBtn must NOT be hidden when VCR.mode === LIVE — operator needs it to adjust live-anim speed');
+});
+
+console.log(`\n=== ${passed} passed, ${failed} failed ===`);
+process.exit(failed === 0 ? 0 : 1);