Feedback round 3: metronome/phrase integration, 16ths, count-in badge, wider transpose

- Metronome/phrase: 'With tempo' renamed to 'Sync to metronome' (auto-enables
  the metronome when selected); phrase click now yields to the metronome
  click (no more double clicks) with an explicit opt-out checkbox.
- Count-in: subtle numeric badge next to the status line (muted pill, 11px).
- Melody rhythm level 3 'Elaborate': sixteenth/dotted-eighth templates for
  4/4 and 3/4; renderer supports 120/360-tick codes and beams 16th pairs.
- Transpose control for library/import material widened to ±2 octaves.
- Tests 161/161 (bar-total invariants hold over 500 seeds at level 2).

src/music/melodyBarTotal.test.ts

@@ -0,0 +1,29 @@
+import { describe, it, expect } from 'vitest';
+import { generateMelody } from './melodyGenerator';
+import { scoreEvents, validateScore } from '../score/model';
+
+// Reproduce user report: "bei 4/4 manchmal 5 Viertel in bar 2"
+describe('melody generator bar totals (4/4, level 2)', () => {
+    const strings = [40, 45, 50, 55, 59, 64];
+    const pool: number[] = [];
+    for (const open of strings) for (let f = 0; f <= 12; f++) pool.push(open + f);
+
+    it('bar 2 always totals exactly one bar', () => {
+        let checked = 0;
+        for (let seed = 1; seed <= 500; seed++) {
+            const r = generateMelody(
+                { keyTonic: 'C', keyMode: 'major', bars: 2, meter: { numerator: 4, denominator: 4 }, rhythmLevel: 2, seed },
+                pool,
+            );
+            if (!r.ok) continue;
+            checked++;
+            const ev = scoreEvents(r.value.score);
+            const problems = validateScore(r.value.score);
+            expect(problems, `seed ${seed}`).toEqual([]);
+            const bar2 = ev.filter(e => e.startTick >= 1920 && e.startTick < 3840);
+            const bar2Len = bar2.reduce((a, e) => a + e.durationTicks, 0);
+            expect(bar2Len, `seed ${seed} bar2 ticks`).toBe(1920);
+        }
+        expect(checked).toBeGreaterThan(400);
+    });
+});

src/music/melodyGenerator.ts

@@ -31,8 +31,9 @@ export interface MelodyConfig {
     /** 1..8 */
     readonly bars: number;
     readonly meter: { readonly numerator: 3 | 4; readonly denominator: 4 };
-    /** 1 = Simple (quarters/halves/wholes), 2 = Mixed (+ paired eighths, dotted quarters). */
-    readonly rhythmLevel: 1 | 2;
+    /** 1 = Simple (quarters/halves/wholes), 2 = Mixed (+ paired eighths, dotted quarters),
+     *  3 = Elaborate (+ sixteenths, sixteenth groups, dotted eighths). */
+    readonly rhythmLevel: 1 | 2 | 3;
     readonly seed: number;
 }
 
@@ -53,6 +54,17 @@ const TEMPLATES_4_L2: number[][] = [
     [720, 720, 480],
     [720, 480, 240, 240, 240],
 ];
+// Level 3: sixteenth-note material (120 = 16th, 360 = dotted 8th).
+const TEMPLATES_4_L3: number[][] = [
+    [480, 480, 120, 120, 120, 120, 480],
+    [120, 120, 120, 120, 480, 480, 480],
+    [480, 120, 120, 120, 120, 480, 480],
+    [360, 120, 480, 480, 480],
+    [480, 360, 120, 480, 480],
+    [120, 120, 120, 120, 120, 120, 120, 120, 480, 480],
+    [480, 480, 360, 120, 480],
+    [720, 120, 120, 120, 120, 480],
+];
 const TEMPLATES_3_L1: number[][] = [
     [480, 480, 480],
     [960, 480],
@@ -65,11 +77,19 @@ const TEMPLATES_3_L2: number[][] = [
     [720, 720],
     [720, 240, 240, 240],
 ];
+// Level 3 for 3/4: sixteenth material filling 1440 ticks.
+const TEMPLATES_3_L3: number[][] = [
+    [480, 120, 120, 120, 120, 480, 480],
+    [120, 120, 120, 120, 480, 480, 480],
+    [360, 120, 480, 480, 480],
+    [480, 360, 120, 480, 480],
+    [120, 120, 120, 120, 120, 120, 120, 120, 480],
+];
 
-function templatesFor(meter: { numerator: 3 | 4 }, level: 1 | 2): number[][] {
+function templatesFor(meter: { numerator: 3 | 4 }, level: 1 | 2 | 3): number[][] {
     const base = meter.numerator === 4
-        ? (level === 1 ? TEMPLATES_4_L1 : [...TEMPLATES_4_L1, ...TEMPLATES_4_L2])
-        : (level === 1 ? TEMPLATES_3_L1 : [...TEMPLATES_3_L1, ...TEMPLATES_3_L2]);
+        ? (level === 1 ? TEMPLATES_4_L1 : level === 2 ? [...TEMPLATES_4_L1, ...TEMPLATES_4_L2] : [...TEMPLATES_4_L1, ...TEMPLATES_4_L2, ...TEMPLATES_4_L3])
+        : (level === 1 ? TEMPLATES_3_L1 : level === 2 ? [...TEMPLATES_3_L1, ...TEMPLATES_3_L2] : [...TEMPLATES_3_L1, ...TEMPLATES_3_L2, ...TEMPLATES_3_L3]);
     return base.filter(t => t.reduce((a, b) => a + b, 0) === meter.numerator * PPQ);
 }