feat: professional reggaeton production engine — 7 SDD changes, 302 tests

- section-energy: track activity matrix + volume/velocity multipliers per section
- smart-chords: ChordEngine with voice leading, inversions, 4 emotion modes
- hook-melody: melody engine with hook/stabs/smooth styles, call-and-response
- mix-calibration: Calibrator module (LUFS volumes, HPF/LPF, stereo, sends, master)
- transitions-fx: FX track with risers/impacts/sweeps at section boundaries
- sidechain: MIDI CC11 bass ducking on kick hits via DrumLoopAnalyzer
- presets-pack: role-aware plugin presets (Serum/Decapitator/Omnisphere per role)

Full SDD pipeline (propose→spec→design→tasks→apply→verify) for all 7 changes.
302/302 tests passing.

tests/test_core_schema.py

@@ -1,12 +1,60 @@
-"""Tests for src/core/schema.py — SongDefinition, TrackDef, ClipDef, MidiNote."""
+"""Tests for src/core/schema.py — SongDefinition, TrackDef, ClipDef, MidiNote, CCEvent."""
 
+import dataclasses
 import sys
 from pathlib import Path
 
 sys.path.insert(0, str(Path(__file__).parents[1]))
 
 import pytest
-from src.core.schema import SongDefinition, SongMeta, TrackDef, ClipDef, MidiNote
+from src.core.schema import SongDefinition, SongMeta, TrackDef, ClipDef, MidiNote, CCEvent
+
+
+class TestCCEvent:
+    """Test CCEvent dataclass (Phase 1: schema)."""
+
+    def test_ccevent_round_trip(self):
+        """CCEvent round-trips correctly through dataclass construction."""
+        evt = CCEvent(controller=11, time=0.5, value=50)
+        assert evt.controller == 11
+        assert evt.time == 0.5
+        assert evt.value == 50
+
+    def test_ccevent_defaults(self):
+        """CCEvent has no default fields — all are required."""
+        from dataclasses import fields as dc_fields
+        field_names = [f.name for f in dc_fields(CCEvent)]
+        no_default = []
+        for f in dc_fields(CCEvent):
+            if f.default is f.default_factory is dataclasses.MISSING:
+                no_default.append(f.name)
+        assert "controller" in no_default
+        assert "time" in no_default
+        assert "value" in no_default
+
+    def test_clipdef_with_midi_cc(self):
+        """ClipDef with midi_cc field."""
+        cc = [CCEvent(11, 0.0, 50), CCEvent(11, 0.18, 127)]
+        clip = ClipDef(position=0.0, length=16.0, name="Test", midi_cc=cc)
+        assert len(clip.midi_cc) == 2
+        assert clip.midi_cc[0].controller == 11
+        assert clip.midi_cc[0].time == 0.0
+        assert clip.midi_cc[0].value == 50
+
+    def test_clipdef_midi_cc_default_is_empty(self):
+        """ClipDef.midi_cc defaults to empty list."""
+        clip = ClipDef(position=0.0, length=16.0, name="Test")
+        assert clip.midi_cc == []
+
+    def test_song_validate_empty_midi_cc(self):
+        """Song.validate() passes with empty midi_cc (no regression)."""
+        meta = SongMeta(bpm=95, key="Am")
+        note = MidiNote(pitch=60, start=0.0, duration=1.0, velocity=100)
+        clip = ClipDef(position=0.0, length=16.0, name="Test", midi_notes=[note], midi_cc=[])
+        track = TrackDef(name="Test", clips=[clip])
+        song = SongDefinition(meta=meta, tracks=[track])
+        errors = song.validate()
+        assert errors == []
 
 
 class TestSongDefinitionInstantiation:
@@ -135,3 +183,30 @@ class TestMidiNote:
         """MidiNote does NOT clamp — accepts any int (caller's responsibility)."""
         note = MidiNote(pitch=60, start=0.0, duration=1.0, velocity=200)
         assert note.velocity == 200
+
+
+class TestClipDefVolMult:
+    """Test ClipDef.vol_mult default and behavior."""
+
+    def test_vol_mult_default_is_one(self):
+        """ClipDef.vol_mult defaults to 1.0."""
+        clip = ClipDef(position=0.0, length=16.0, name="Test")
+        assert clip.vol_mult == 1.0
+
+    def test_vol_mult_custom_value(self):
+        """ClipDef.vol_mult accepts custom value."""
+        clip = ClipDef(position=0.0, length=16.0, name="Test", vol_mult=0.7)
+        assert clip.vol_mult == 0.7
+
+    def test_audio_clip_vol_mult_default_is_one(self):
+        """Audio clip with default vol_mult=1.0 has no D_VOL side effect."""
+        clip = ClipDef(position=0.0, length=16.0, audio_path="test.wav", vol_mult=1.0)
+        assert clip.is_audio
+        assert clip.vol_mult == 1.0
+
+    def test_midi_clip_vol_mult_default_is_one(self):
+        """MIDI clip with default vol_mult=1.0 has no velocity scaling."""
+        note = MidiNote(pitch=60, start=0.0, duration=1.0, velocity=100)
+        clip = ClipDef(position=0.0, length=16.0, midi_notes=[note], vol_mult=1.0)
+        assert clip.is_midi
+        assert clip.vol_mult == 1.0