feat: release 1.5.4 - steering, Asset Library, canvas delete, agent hardening
- Mid-run steering input in AI Canvas + Build Scene (steering/message event, step-boundary drain, composer Steer mode)
- New /library Asset Library page: unlinked Playground media with All/Image/Video filters, 50-per-page lazy loading, bulk delete, add-to-project
- AI Canvas delete now persists: reference-checked file cleanup for playground-owned artifacts, entity tombstones, canvas.updated sync
- Agent loop hardening batch: swarm safety nets, clip tools in roles, capture false-success fix, planner fast-path, per-tool timeout, char-bounded history
- Build Scene Brief/Cut gates + MP4 export normalization
Benjiyaya
ee7648d957