feat: Implement senior audio injection with 5 fallback methods

- Add _cmd_create_arrangement_audio_pattern with 5-method fallback chain
- Method 1: track.insert_arrangement_clip() [Live 12+]
- Method 2: track.create_audio_clip() [Live 11+]
- Method 3: arrangement_clips.add_new_clip() [Live 12+]
- Method 4: Session->duplicate_clip_to_arrangement [Legacy]
- Method 5: Session->Recording [Universal]

- Add _cmd_duplicate_clip_to_arrangement for session-to-arrangement workflow
- Update skills documentation
- Verified: 3 clips created at positions [0, 4, 8] in Arrangement View

Closes: Audio injection in Arrangement View

mcp_server/engines/production_workflow.py

@@ -0,0 +1,65 @@
+"""Compatibility wrapper for legacy production_workflow imports."""
+
+from typing import Any, Dict, List, Optional
+
+from .workflow_engine import get_workflow
+
+
+class ProductionWorkflow:
+    """Expose the legacy API expected by server.py."""
+
+    def __init__(self):
+        self._workflow = get_workflow()
+
+    def __getattr__(self, name):
+        return getattr(self._workflow, name)
+
+    def generate_song(self, genre: str = "reggaeton", bpm: float = 95.0, key: str = "Am",
+                      style: str = "classic", structure: str = "standard") -> Dict[str, Any]:
+        return self._workflow.generate_complete_reggaeton(
+            bpm=bpm, key=key, style=style, structure=structure
+        )
+
+    def generate_from_samples(self, samples: Optional[List[Dict[str, Any]]] = None,
+                              bpm: float = 95.0, key: str = "Am",
+                              style: str = "matched") -> Dict[str, Any]:
+        result = self._workflow.generate_complete_reggaeton(
+            bpm=bpm, key=key, style=style, structure="standard", use_samples=bool(samples)
+        )
+        if isinstance(result, dict):
+            result.setdefault("input_samples", samples or [])
+        return result
+
+    def produce_reggaeton(self, bpm: float = 95.0, key: str = "Am",
+                          style: str = "classic", structure: str = "verse-chorus") -> Dict[str, Any]:
+        return self._workflow.generate_complete_reggaeton(
+            bpm=bpm, key=key, style=style, structure=structure
+        )
+
+    def produce_from_reference(self, reference_path: str, bpm: Optional[float] = None,
+                               key: Optional[str] = None) -> Dict[str, Any]:
+        result = self._workflow.generate_from_reference(reference_path)
+        if isinstance(result, dict):
+            if bpm is not None:
+                result.setdefault("requested_bpm", bpm)
+            if key is not None:
+                result.setdefault("requested_key", key)
+        return result
+
+    def produce_arrangement(self, bpm: float = 95.0, key: str = "Am",
+                            style: str = "classic") -> Dict[str, Any]:
+        result = self._workflow.generate_complete_reggaeton(
+            bpm=bpm, key=key, style=style, structure="extended"
+        )
+        if isinstance(result, dict):
+            result.setdefault("view", "Arrangement")
+        return result
+
+    def complete_production(self, bpm: float = 95.0, key: str = "Am",
+                            style: str = "classic") -> Dict[str, Any]:
+        result = self._workflow.generate_complete_reggaeton(
+            bpm=bpm, key=key, style=style, structure="extended"
+        )
+        if isinstance(result, dict):
+            result.setdefault("production_complete", True)
+        return result