docs: add meta-inventory project manifest

[hubofwyn]

What changed

• add the root project.yaml v0.1 interoperability manifest
• preserve WynIsBuff2 as an independent canonical project with no relationship to Wyn der Schrank
• align the status authority with current remote and GitHub facts

Why

Meta-inventory requires a committed default-branch manifest with a case-sensitive remote join key, registered owner entity, quoted as_of, valid ontology values, and an explicit status-of-record path.

Impact

This allows meta-inventory to harvest WynIsBuff2 as a first-class public project without claiming a deployment or current active development.

Validation

• meta-inventory parser: 0 manifest errors
• meta-inventory graph validation: 0 errors
• producer self-check: OK
• bun test
• bun run lint
• bun run lint:boundaries
• bun run arch:health
• bun run deps:check
• bun run build-nolog
• Markdown lint and git diff --check