Chakra: add key variable, picker shows (multi) for multi-key tracks

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

play.py

@@ -404,7 +404,13 @@ def pick_track():
             m = int(duration_sec // 60)
             s = int(duration_sec % 60)
             pitch = score.reference_pitch if score.reference_pitch != 440.0 else None
-            track_key = str(getattr(mod, 'key', '')) if hasattr(mod, 'key') else ""
+            # Detect multi-key tracks
+            if hasattr(mod, 'key_lower'):
+                track_key = "(multi)"
+            elif hasattr(mod, 'key'):
+                track_key = str(mod.key)
+            else:
+                track_key = ""
             tuning = ""
             if score.system != "western":
                 tuning = score.system

tracks/chakra.py

@@ -31,6 +31,7 @@ score = Score("4/4", bpm=60, system="shruti", reference_pitch=432.0)
 # Throat/Third Eye: E major (bright, expressive)
 # Crown: dissolves into pure frequency
 
+key = Key("G", "major")          # primary key (multi-key track)
 key_lower = Key("G", "major")    # root, sacral
 key_middle = Key("C", "major")   # solar, heart
 key_upper = Key("E", "major")    # throat, third eye