chore: (optimization) add provenance file + register with release please

[andrewklatzke]

Requirements

• I have added test coverage for new or changed functionality
• I have followed the repository's pull request submission guidelines
• I have validated my changes against all supported platform versions

Describe the solution you've provided

This adds a PROVENANCE.md file and registers it with release-please.

Describe alternatives you've considered

No alternatives here; required for security

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Note

Low Risk
Low risk: documentation-only addition plus a release configuration tweak to include PROVENANCE.md in version bumps; no runtime code changes.

Overview
Adds a new packages/optimization/PROVENANCE.md documenting how to verify published wheel provenance using GitHub artifact attestations.

Updates release-please-config.json so packages/optimization treats PROVENANCE.md as an extra-file, ensuring the doc’s embedded version snippet is kept in sync during releases.

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