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

docs/migration_report_20260411_220208.md

@@ -0,0 +1,72 @@
+# AbletonMCP_AI Senior Architecture Migration Report
+
+**Migration:** Senior Architecture Migration
+**Version:** 1.0.0
+**Started:** 2026-04-11T22:02:08.964978
+**Completed:** 2026-04-11T22:02:08.965585
+**Overall Status:** SUCCESS
+
+---
+
+## Step Results
+
+| Step | Status | Message | Duration |
+|------|--------|---------|----------|
+| check_prerequisites | [OK] Success | All prerequisites met | 0.00s |
+
+---
+
+## Summary
+
+- **Total steps:** 1
+- **Success:** 1
+- **Failed:** 0
+- **Warnings:** 0
+- **Skipped:** 0
+
+---
+
+## Next Steps
+
+1. [OK] Restart Ableton Live to load the updated Remote Script
+2. [OK] Run 'health_check' to verify the installation
+3. [OK] Try 'build_song' to test the new arrangement features
+4. [OK] Check the documentation in docs/ for new features
+
+---
+
+## Detailed Information
+
+### Full Results JSON
+
+```json
+{
+  "migration_name": "Senior Architecture Migration",
+  "version": "1.0.0",
+  "started_at": "2026-04-11T22:02:08.964978",
+  "completed_at": "2026-04-11T22:02:08.965585",
+  "steps": [
+    {
+      "name": "check_prerequisites",
+      "status": "success",
+      "message": "All prerequisites met",
+      "details": {
+        "python_version": "3.14.4",
+        "python_ok": true,
+        "ableton_path": "C:\\ProgramData\\Ableton\\Live 12 Suite\\Resources\\MIDI Remote Scripts",
+        "ableton_exists": true,
+        "project_exists": true,
+        "write_permissions": true,
+        "disk_free_mb": 268040.98,
+        "disk_ok": true,
+        "migrate_library_script_exists": true,
+        "test_arrangement_script_exists": true,
+        "errors": [],
+        "warnings": []
+      },
+      "duration_seconds": 0.000562,
+      "timestamp": "2026-04-11T22:02:08.965562"
+    }
+  ]
+}
+```