nosi 2026.W26

nosi image catalog (schema v1). Two flavours:

• catalog.toml : refs pinned to :2026.W26; reproducible flashes
• catalog-latest.toml : refs as :latest; rolling escape hatch

Flash with bty:

bty --catalog https://github.com/safl/nosi/releases/latest/download/catalog.toml

The layer digest is verified at flash time regardless of tag policy.