phase5: mặc định RENDER_ENGINE=bridge, gỡ pedalboard khỏi requirements/source/LICENSE

- config.py: SF_RENDER_ENGINE default 'bridge' (pedalboard GPL-3.0 đã gỡ)
- requirements.txt: bỏ pedalboard==0.9.19
- vst_engine.py: bỏ HAS_PEDALBOARD/check_pedalboard_safe/load_vst/import pedalboard;
  midi_events_to_messages giữ làm utility thuần (không gate pedalboard)
- render_engine.py: bỏ nhánh elif vst and HAS_PEDALBOARD + import thừa
- plugins.py: preview/midi-render chỉ qua native_bridge; guard SF_RENDER_ENGINE=bridge
- runtime.py: _vst_render_available() check bridge exe (SF_BRIDGE_PATH/install/) thay find_spec('pedalboard')
- LICENSE.md/THIRD_PARTY_LICENSES.md: bỏ cảnh báo GPL-3.0 pedalboard, đánh số lại
- tests: bỏ test golden so pedalboard + test requires_pedalboard; 114 passed 0 skip

app/core/render_engine.py

@@ -6,10 +6,7 @@ import soundfile as sf
 from app.config import settings
 from app.core.vst_engine import (
     render_midi_events_to_audio,
-    PluginManager,
-    HAS_PEDALBOARD,
     HAS_PYFLUIDSYNTH,
-    apply_preset_to_plugin,
     RENDER_LOCK,
 )
 
@@ -199,9 +196,6 @@ class PythonRenderEngine:
                     
                     if midi_events:
                         try:
-                            plugin_mgr = PluginManager()
-                            vst = plugin_mgr.load_vst(instrument_id) if instrument_id else None
-
                             if instrument_source == "pianobook":
                                 # Phase 4 (§3.4): .dspreset không hỗ trợ nữa (pedalboard
                                 # GPL-3.0 gỡ; spike load .dspreset fail). Chặn + fallback synth.
@@ -214,8 +208,8 @@ class PythonRenderEngine:
                                     midi_events=midi_events, sr=self.sample_rate, bpm=bpm, instrument='synth'
                                 )
                             elif instrument_id and not instrument_id.startswith("sf_"):
-                                # VSTi track: native_bridge --render (SF_RENDER_ENGINE=bridge)
-                                # thay pedalboard; ngược lại giữ pedalboard path cũ.
+                                # VSTi track: native_bridge --render (SF_RENDER_ENGINE=bridge).
+                                # Giá trị engine khác → fallback synth (pedalboard GPL-3.0 đã gỡ).
                                 if settings.RENDER_ENGINE == "bridge":
                                     try:
                                         from app.core import native_render
@@ -251,38 +245,7 @@ class PythonRenderEngine:
                                         synth_buffer = render_midi_events_to_audio(
                                             midi_events=midi_events, sr=self.sample_rate, bpm=bpm, instrument='synth'
                                         )
-                                elif vst and HAS_PEDALBOARD:
-                                    from pedalboard import Pedalboard
-                                    # Preset bridge Carla → pedalboard: preset_id
-                                    # (thư viện storage/presets), preset_path (file)
-                                    # hoặc preset_data (base64 .vstpreset nhúng trong
-                                    # project). Cùng sample rate → âm render = âm đã
-                                    # chỉnh trong Carla.
-                                    try:
-                                        se2 = track.get("synth_engine", {}) or {}
-                                        apply_preset_to_plugin(
-                                            vst,
-                                            preset_id=se2.get("preset_id") or track.get("preset_id"),
-                                            preset_path=se2.get("preset_path") or track.get("preset_path"),
-                                            preset_data_b64=se2.get("preset_data") or track.get("preset_data"),
-                                        )
-                                    except Exception as e:
-                                        logger.warning("[RenderEngine] Preset apply failed: %s", e)
-                                    midi_messages = PluginManager.midi_events_to_messages(
-                                        midi_events, bpm, self.sample_rate,
-                                        bank=soundfont_bank, program=soundfont_program
-                                    )
-                                    total_needed = 0
-                                    for ev in midi_events:
-                                        end_sec = (ev.get("start_beat", 0) + ev.get("duration_beats", 1)) * (60.0 / bpm)
-                                        dur_samples = int(end_sec * self.sample_rate)
-                                        if dur_samples > total_needed:
-                                            total_needed = dur_samples
-                                    total_needed = max(total_needed, 1024)
-                                    silent = np.zeros((2, total_needed), dtype=np.float32)
-                                    # pedalboard >= 0.9: instrument KHÔNG vào Pedalboard container
-                                    synth_buffer = vst(midi_messages, sample_rate=self.sample_rate,
-                                                       duration=total_needed / float(self.sample_rate), num_channels=2)
+
                                 else:
                                     synth_buffer = render_midi_events_to_audio(
                                         midi_events=midi_events, sr=self.sample_rate, bpm=bpm, instrument='synth'