Implement FASE 3, 4, 6 - 15 new MCP tools, 76/110 tasks complete

FASE 3 - Human Feel & Dynamics (10/11 tasks):
- apply_clip_fades() - T041: Fade automation per section
- write_volume_automation() - T042: Curves (linear, exp, s_curve, punch)
- apply_sidechain_pump() - T045: Sidechain by intensity/style
- inject_pattern_fills() - T048: Snare rolls, fills by density
- humanize_set() - T050: Timing + velocity + groove automation

FASE 4 - Key Compatibility & Tonal (9/12 tasks):
- audio_key_compatibility.py: Full KEY_COMPATIBILITY_MATRIX
- analyze_key_compatibility() - T053: Harmonic compatibility scoring
- suggest_key_change() - T054: Circle of fifths modulation
- validate_sample_key() - T055: Sample key validation
- analyze_spectral_fit() - T057/T062: Spectral role matching

FASE 6 - Mastering & QA (8/13 tasks):
- calibrate_gain_staging() - T079: Auto gain by bus targets
- run_mix_quality_check() - T085: LUFS, peaks, L/R balance
- export_stem_mixdown() - T087: 24-bit/44.1kHz stem export

New files:
- audio_key_compatibility.py (T052)
- bus_routing_fix.py (T101-T104)
- validation_system_fix.py (T105-T106)

Total: 76/110 tasks (69%), 71 MCP tools exposed

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

AbletonMCP_AI/MCP_Server/tests/test_human_feel.py

@@ -0,0 +1,75 @@
+"""
+test_human_feel.py - Tests para HumanFeelEngine
+T101-T103: Unit tests
+"""
+import sys
+import os
+sys.path.insert(0, os.path.dirname(os.path.dirname(os.path.abspath(__file__))))
+
+import unittest
+from human_feel import HumanFeelEngine
+
+
+class TestHumanFeelEngine(unittest.TestCase):
+    """Tests para HumanFeelEngine"""
+
+    def setUp(self):
+        self.engine = HumanFeelEngine(seed=42)
+
+    def test_timing_variation_range(self):
+        """T040: Timing variation dentro de rango ±5ms."""
+        notes = [{'pitch': 60, 'start': 0.0, 'velocity': 100}]
+        result = self.engine.apply_timing_variation(notes, amount_ms=5.0)
+
+        for note in result:
+            offset_ms = (note['start'] - 0.0) * 1000
+            self.assertGreaterEqual(offset_ms, -5.0)
+            self.assertLessEqual(offset_ms, 5.0)
+
+    def test_velocity_humanize_variance(self):
+        """T041: Velocity variation ±5%."""
+        notes = [{'pitch': 60, 'start': 0.0, 'velocity': 100}]
+        result = self.engine.apply_velocity_humanize(notes, variance=0.05)
+
+        for note in result:
+            # Velocity debe estar en rango 95-105
+            self.assertGreaterEqual(note['velocity'], 95)
+            self.assertLessEqual(note['velocity'], 105)
+
+    def test_note_skip_probability(self):
+        """T042: Probabilidad de skip ~2%."""
+        notes = [{'pitch': 60, 'start': float(i), 'velocity': 100} for i in range(100)]
+        result = self.engine.apply_note_skip_probability(notes, prob=0.02)
+
+        # Con seed=42, debe mantener aprox 98% de notas
+        self.assertGreater(len(result), 90)  # No muy estricto por randomness
+        self.assertLess(len(result), 100)
+
+    def test_section_dynamics_scale(self):
+        """T047-T050: Dinámica por sección."""
+        notes = [{'pitch': 60, 'start': 0.0, 'velocity': 100}]
+
+        # Intro = 70%
+        intro_notes = self.engine.apply_section_dynamics(notes, 'intro')
+        self.assertEqual(intro_notes[0]['velocity'], 70)
+
+        # Drop = 100%
+        drop_notes = self.engine.apply_section_dynamics(notes, 'drop')
+        self.assertEqual(drop_notes[0]['velocity'], 100)
+
+        # Build = 85%
+        build_notes = self.engine.apply_section_dynamics(notes, 'build')
+        self.assertEqual(build_notes[0]['velocity'], 85)
+
+    def test_groove_applies_to_offbeat(self):
+        """T044-T046: Groove aplica a notas off-beat."""
+        # Nota en off-beat (beat position 0.5)
+        notes = [{'pitch': 60, 'start': 4.5, 'velocity': 100}]
+        result = self.engine.apply_groove(notes, style='shuffle', amount=1.0)
+
+        # Debe tener delay aplicado
+        self.assertGreater(result[0]['start'], 4.5)
+
+
+if __name__ == '__main__':
+    unittest.main()