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_sample_selector.py

@@ -0,0 +1,77 @@
+"""
+test_sample_selector.py - Tests para SampleSelector
+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 unittest.mock import Mock, MagicMock
+from sample_selector import SampleSelector, Sample
+
+
+class TestSampleSelector(unittest.TestCase):
+    """Tests para SampleSelector"""
+
+    def setUp(self):
+        self.selector = SampleSelector()
+
+    def test_palette_bonus_exact_match(self):
+        """T026: Bonus 1.4x para folder ancla exacto."""
+        # Simular que tenemos un palette
+        self.selector.set_palette_data({'drums': '/samples/Kicks'})
+
+        # Sample en folder exacto
+        bonus = self.selector._calculate_palette_bonus('/samples/Kicks/kick_01.wav', '/samples/Kicks')
+        self.assertEqual(bonus, 1.4)
+
+    def test_palette_bonus_sibling_folder(self):
+        """T026: Bonus 1.2x para folder hermano."""
+        self.selector.set_palette_data({'drums': '/samples/Kicks'})
+
+        # Sample en folder hermano
+        bonus = self.selector._calculate_palette_bonus('/samples/Snares/snare_01.wav', '/samples/Kicks')
+        self.assertEqual(bonus, 1.2)
+
+
+    def test_palette_bonus_different_folder(self):
+        """T026: Penalizacion 0.9x para folder completamente diferente."""
+        self.selector.set_palette_data({'drums': '/Library/Kicks'})
+
+        # Sample en folder completamente diferente (no es hermano)
+        bonus = self.selector._calculate_palette_bonus('/OtherLibrary/Pads/pad.wav', '/Library/Kicks')
+        self.assertEqual(bonus, 0.9)
+
+    def test_role_to_bus_mapping(self):
+        """Test mapeo de roles a buses."""
+        self.assertEqual(self.selector._role_to_bus('kick'), 'drums')
+        self.assertEqual(self.selector._role_to_bus('bass'), 'bass')
+        self.assertEqual(self.selector._role_to_bus('synth'), 'music')
+
+    def test_fatigue_calculation(self):
+        """T022: Cálculo correcto de fatiga."""
+        fatigue_data = {
+            '/samples/kick_01.wav': {'kick': {'uses': 5}}
+        }
+        self.selector.set_fatigue_data(fatigue_data)
+
+        # 5 usos = fatiga moderada = 0.50
+        factor = self.selector._get_persistent_fatigue('/samples/kick_01.wav', 'kick')
+        self.assertEqual(factor, 0.50)
+
+
+class TestSampleValidation(unittest.TestCase):
+    """Tests para validación de samples"""
+
+    def test_sample_type_detection(self):
+        """Test detección de tipo de sample."""
+        from audio_analyzer import AudioAnalyzer
+
+        analyzer = AudioAnalyzer(backend="basic")
+        sample_type = analyzer._classify_by_name("Kick_120_BPM.wav")
+        self.assertIn(sample_type.value.lower(), ['kick', 'unknown'])
+
+
+if __name__ == '__main__':
+    unittest.main()