v4.3.0 — portability trim

This release makes skill-provenance lighter and more portable across models and surfaces by tightening the core protocol and downgrading surface-specific conveniences from defaults to optional artifacts.

What changed

• Simplified the core protocol around the truly portable bundle artifacts:
  MANIFEST.yaml, CHANGELOG.md, and the tracked bundle files.
• Made handoff.md optional instead of a default bundle requirement.
  Handoff notes are now recommended mainly for stateless chat transitions.
• Changed git commit output to inline-by-default.
  git_commit.txt is now an optional convenience artifact rather than a standard expected output.
• Reworked compatibility metadata to describe target surfaces and capabilities instead of pinning the bundle to a single exact model/surface tuple.
• Reduced Claude-first wording in the documentation and added clearer Codex loading guidance.
• Updated evals so portability-oriented behavior is the default:
  chat handoff is still validated where appropriate, but handoff.md and git_commit.txt are no longer universal success criteria.

Why this release

The goal of this update is to keep the bundle maximally portable and lightweight across Claude, Codex, Gemini CLI, and similar agents without carrying extra workflow assumptions from any one surface.

Files changed

• SKILL.md
  Refined the protocol so transient artifacts are optional and compatibility guidance is capability-based.
• README.md
  Reworked user guidance for a more agent-agnostic, lightweight workflow.
• evals.json
  Updated expectations to match the new portability-first protocol.
• MANIFEST.yaml
  Bumped bundle version and updated compatibility metadata.
• CHANGELOG.md
  Added the 4.3.0 release entry.

Validation

• ./validate.sh passes with all hashes verified.
• Rebuilt skill-provenance.skill from the updated bundle.