feat: CC11 expression automation (spec midi_note_cc11_expression)

- MIDINote schema + expression_curve (position_ratio 0..1, value 0..127)
- Piano roll CC lane mode Expression (CC11): draw/move/del anchors
- Offline: _expression_events grid 64 samples -> job.events -> RenderJob.cpp sample-accurate CC
- Realtime: scheduleNoteExpressionCC11 grid 16ms via bridge pushEvent / SonicSF fallback, epoch-guarded, cleared on stop
- tests/test_cc11_expression.py 6/6 (unit interp/grid/clamp + integration energy follows curve)
- rebuild daw_vst_bridge (narrowing fix) + sync binaries/dist, babel rebuild + sync 5 copies

app/core/native_render.py

@@ -175,6 +175,60 @@ def bridge_state_preset_b64(channel=None, plugin_path=None) -> str:
     return ""
 
 
+def _expression_events(notes, bpm, sample_rate, grid=64):
+    """Sinh CC11 events sample-accurate từ expression_curve mỗi note.
+
+    curve: [{position_ratio 0..1, value 0..127}] — nội suy tuyến tính, grid
+    cố định (mặc định 64 samples ≈ 1.3ms @48k) → step CC <= 1-2, không zipper.
+    Event shape {sample, kind:2, a:11, b:value} — khớp RenderJob.cpp Ev.
+    """
+    if not notes or not bpm:
+        return []
+    beat_sec = 60.0 / float(bpm)
+    events = []
+    for n in notes:
+        curve = n.get("expression_curve") if isinstance(n, dict) else None
+        if not curve:
+            continue
+        try:
+            pts = sorted((float(p["position_ratio"]), int(round(float(p["value"])))) for p in curve if p)
+        except Exception:
+            continue
+        if not pts:
+            continue
+        start_sample = int(round(float(n.get("start_beat", 0)) * beat_sec * float(sample_rate)))
+        dur_samples = int(round(float(n.get("duration_beats", 1)) * beat_sec * float(sample_rate)))
+        if dur_samples <= 0:
+            continue
+
+        def interp(ratio):
+            ratio = max(0.0, min(1.0, ratio))
+            if len(pts) == 1:
+                return pts[0][1]
+            if ratio <= pts[0][0]:
+                return pts[0][1]
+            if ratio >= pts[-1][0]:
+                return pts[-1][1]
+            for i in range(1, len(pts)):
+                if ratio <= pts[i][0]:
+                    a, b = pts[i - 1], pts[i]
+                    t = (ratio - a[0]) / (b[0] - a[0]) if b[0] > a[0] else 0.0
+                    return int(round(a[1] + (b[1] - a[1]) * t))
+            return pts[-1][1]
+
+        pos = 0
+        while pos <= dur_samples:
+            ratio = pos / float(dur_samples)
+            events.append({
+                "sample": start_sample + int(pos),
+                "kind": 2,
+                "a": 11,
+                "b": max(0, min(127, interp(ratio))),
+            })
+            pos += max(1, int(grid))
+    events.sort(key=lambda e: e["sample"])
+    return events
+
 def _run_notes_job(job: dict, label: str) -> tuple:
     """Chạy job MIDI render qua native_bridge --render → (out_path, duration_sec).
 
@@ -279,6 +333,9 @@ def render_offline(instrument_id, notes, bpm, sample_rate, preset_id=None,
         job["soundfont_bank"] = int(soundfont_bank) & 0x7F
     if soundfont_program is not None:
         job["soundfont_program"] = int(soundfont_program) & 0x7F
+    events = _expression_events(notes, bpm, sample_rate)
+    if events:
+        job["events"] = events
     return _run_notes_job(job, instrument_id)
 
 
@@ -303,6 +360,9 @@ def render_soundfont_offline(sf_path, notes, bpm, sample_rate, bank=0, program=0
             "duration_beats": float(n.get("duration_beats", 1)),
         } for n in notes],
     }
+    events = _expression_events(notes, bpm, sample_rate)
+    if events:
+        job["events"] = events
     return _run_notes_job(job, os.fspath(sf_path))