The prior README asset kept the generated black canvas, which made the logo render as a dark rectangle instead of a standalone mark. The PNG is now edge-flooded to alpha and trimmed, with README sizing adjusted for the cropped portrait asset.

Constraint: Use the existing generated logo and avoid changing README content beyond display size.

Rejected: Remove all near-black pixels | would damage shadows and the dark stone base.

Confidence: high

Scope-risk: narrow

Directive: Preserve alpha transparency when replacing docs/assets/colony-logo.png.

Tested: git diff --check; file docs/assets/colony-logo.png; identify alpha/bounds checks

Not-tested: GitHub rendered README after merge