feat: CC11 expression automation (spec midi_note_cc11_expression)

- MIDINote schema + expression_curve (position_ratio 0..1, value 0..127)
- Piano roll CC lane mode Expression (CC11): draw/move/del anchors
- Offline: _expression_events grid 64 samples -> job.events -> RenderJob.cpp sample-accurate CC
- Realtime: scheduleNoteExpressionCC11 grid 16ms via bridge pushEvent / SonicSF fallback, epoch-guarded, cleared on stop
- tests/test_cc11_expression.py 6/6 (unit interp/grid/clamp + integration energy follows curve)
- rebuild daw_vst_bridge (narrowing fix) + sync binaries/dist, babel rebuild + sync 5 copies

app/models/project_schema.json

@@ -151,7 +151,19 @@
         "start_beat": { "type": "number", "description": "Beat offset relative to the start of the source buffer (bar 0)" },
         "duration_beats": { "type": "number" },
         "velocity": { "type": "number", "minimum": 0.0, "maximum": 1.0, "default": 0.8 },
-        "pan": { "type": "number", "minimum": -1.0, "maximum": 1.0, "default": 0.0 }
+        "pan": { "type": "number", "minimum": -1.0, "maximum": 1.0, "default": 0.0 },
+        "expression_curve": {
+          "type": "array",
+          "description": "CC11 expression automation: normalized position 0..1 in note, value 0..127",
+          "items": {
+            "type": "object",
+            "properties": {
+              "position_ratio": { "type": "number", "minimum": 0.0, "maximum": 1.0 },
+              "value": { "type": "integer", "minimum": 0, "maximum": 127 }
+            },
+            "required": ["position_ratio", "value"]
+          }
+        }
       },
       "required": ["id", "pitch", "start_beat", "duration_beats", "velocity"]
     },