Product exploration: Repaint, stem separation, model marketplace

[thedavidweng]

Problem

Long-term product exploration for features that extend OpenLoop beyond single-shot generation. These are research spikes, not committed roadmap items.

Scope

• Repaint: Waveform drag-select for region, ACE-Step /edit endpoint integration
• Stem separation + MIDI export: Evaluate feasibility, potential OpenKara integration
• Model marketplace: ModelProvider trait abstraction, remote manifest registry for community models

Acceptance criteria

• Each exploration produces a short feasibility doc or ADR
• Repaint spike demonstrates region selection + /edit call
• Stem separation has a working prototype or documented blocker
• Model marketplace has a trait design and manifest format proposal