- Introduce data/research/cargo.json: a 3-node chain (8 → 12 → 16 bays) where each node is a blueprint that unlocks the matching ship-hold build
- Add `build` gate field to ResearchModel.js (attachBuildGates) so a node can require a named build to be completed before it becomes researchable, composing with the existing quest gate
- Wire both gates in GameScene and ResearchWindow so node availability, lock notes, and the RESEARCH button reflect quest + build state
- Gate cargo_bay_8 on the special_delivery quest; cargo_bay_12/16 on Improved/Advanced Mining Storage builds
- Update builds.json to require the corresponding research nodes for cargo-bay-8/-12/-16
- Add comprehensive tests covering the cargo tree structure, pure DAG availability, live gate composition, and build-side lock-step
Brian Fertig
138096cd2b