Per pi.dev/docs/latest/sdk, the ecosystem has moved from
@mariozechner/* to @earendil-works/*. Update all imports,
peerDependencies, devDependencies, and test mocks.

- src/: change all @mariozechner/* imports to @earendil-works/*
- tests: update vi.mock() targets to @earendil-works/*
- peerDeps: add @earendil-works/*, keep @mariozechner/* for transition