fix: show live waveforms on EDIT pages and add DX7 operator controls

- Draw and continuously refresh the output scope on all EDIT and VOICE pages
- Add OP1-OP6 selection and all 21 per-operator fields plus enable controls
- Preserve packed DX7 fields, other operators, and saved user/project data
- Hide DX7-only pages on other engines and after track changes
- Test real EDIT drawing, automatic refresh, operator edits and save/load
- Document hardware page controls and release ALG05 TEST / FM-1_985
