fixture: reconcile awkward-lib published-name collision with current zed CLI #166

Failure

Workflow zed full lifecycle run 32286343496 failed only for zed-pkg-test/awkward-lib; the other lifecycle fixtures and the immutable CLI build passed.

The exact failure is:

invalid manifest .../awkward-lib/.zpkg.toml:
invalid target `repository`: published name `awkward-lib` collides with the polyglot source package

Fixture head observed by the run:

zed-pkg-test/awkward-lib@6ccc922f4cb27b4a3de5f0e113c4bbf20d736300

Required decision

Determine whether awkward-lib is intended to be:

1. a valid full-lifecycle fixture, in which case its repository target/published name must be made unambiguous; or
2. a negative collision fixture, in which case it must move out of the positive lifecycle matrix and gain an explicit expected-failure assertion.

Do not relax the CLI collision validation merely to make the fixture green.

Acceptance criteria

• The fixture's intended positive/negative semantics are explicit.
• A positive fixture completes publish, lock, uninstall, fetch, and replay.
• A negative fixture asserts the exact collision error and is excluded from the positive aggregate gate.
• The full lifecycle workflow is green without weakening manifest validation.

This failure is unrelated to PR #165, which changes only generated source-certification semantics and whose targeted contract passed.