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.

.sdd/changes/sidechain/spec.md

@@ -0,0 +1,76 @@
+# Delta Spec: 808 Bass Sidechain Ducking
+
+## ADDED Requirements
+
+### Requirement: MIDI CC11 Event Data Model
+
+The schema MUST support an `CCEvent` dataclass with controller, time, and value fields, and `ClipDef` MUST accept an optional `midi_cc: list[CCEvent]` field defaulting to empty list.
+
+#### Scenario: CCEvent round-trips correctly
+- GIVEN `CCEvent(controller=11, time=0.5, value=50)`
+- WHEN serialized/deserialized via dataclass
+- THEN all fields preserved exactly
+
+#### Scenario: ClipDef with midi_cc
+- GIVEN a `ClipDef` with `midi_cc=[CCEvent(11, 0.0, 50), CCEvent(11, 0.18, 127)]`
+- WHEN clip is processed by builder
+- THEN builder sees `midi_cc` field and can iterate it
+
+### Requirement: Kick Position Cache
+
+A kick-cache dict `{drumloop_wav_path: list[beat_positions]}` SHALL be computed once per session, keyed by WAV path. `DrumLoopAnalyzer.transient_positions("kick")` MUST be the source, filtered by `confidence >= KICK_CONFIDENCE_THRESHOLD` (default 0.6).
+
+#### Scenario: Cache hit
+- GIVEN drumloop WAV already analyzed in same session
+- WHEN `build_bass_track()` requests kick positions for that path
+- THEN cached positions returned without re-analyzing WAV
+
+#### Scenario: Cache miss
+- GIVEN drumloop WAV not yet cached
+- WHEN kick positions requested
+- THEN `DrumLoopAnalyzer.analyze()` runs, positions cached by path key
+
+### Requirement: CC11 Ducking on Kick Hits
+
+For each kick transient position in the bass clip's time span, the system MUST emit CC11 events forming a ducking envelope: instantaneous drop to value 50 at kick time, hold at 50 for 0.02 beats, ramp to 127 by 0.18 beats after kick.
+
+#### Scenario: Single kick duck
+- GIVEN kick at beat 1.0 within a 4-beat bass clip
+- WHEN CC events generated
+- THEN emits `CCEvent(11, 1.0, 50)`, `CCEvent(11, 1.02, 50)`, `CCEvent(11, 1.18, 127)`
+
+#### Scenario: No kicks in clip
+- GIVEN drumloop with no kick transients in clip time range
+- THEN `midi_cc` is empty list — no CC events emitted
+
+## MODIFIED Requirements
+
+### Requirement: RPPBuilder MIDI Source Encoding
+
+`_build_midi_source()` MUST emit MIDI CC events as `E B0 0B xx` lines interleaved with note events, all sorted by absolute start time. Delta-encoding MUST continue for all E-lines.
+
+#### Scenario: CC events interleaved with notes
+- GIVEN clip with `midi_notes=[Note(60, 0.5, 1.0)]` and `midi_cc=[CCEvent(11, 0.0, 50)]`
+- WHEN `_build_midi_source()` called
+- THEN E-lines emitted in time order: CC at 0.0, Note at 0.5
+- AND CC line reads `E 0 B0 0B 32` (delta=0, CC11, value=50=0x32)
+
+#### Scenario: Delta sequencing across note+CC
+- GIVEN CC at 0.0, note at 0.5 beats
+- WHEN building E-lines
+- THEN CC delta = 0×960 = 0; note delta = 0.5×960 - 0 = 480
+- AND cursor reset correctly after CC event ticks
+
+### Requirement: Bass Track Generation
+
+`build_bass_track()` SHALL accept an optional `kick_cache: dict[str, list[float]]` parameter. When kick data is present for the drumloop used in each section, `midi_cc` events SHALL be generated and added to the bass `ClipDef`.
+
+#### Scenario: Bass clip with ducking CC
+- GIVEN kick cache has `[1.0, 2.5]` for drumloop, section covers beats 0-16
+- WHEN bass track built
+- THEN bass clip at that section has `midi_cc` with 2×3 CC events (one envelope per kick in range)
+- AND note generation unchanged from existing behavior
+
+#### Scenario: No kick cache provided
+- GIVEN `kick_cache` is `{}` or omitted
+- THEN `midi_cc` is empty — zero behavioral change from current output