Add the 'Oracle-to-PostgreSQL Migration Expert' Custom Agent, Associated Skills, and Plugin Manifest

[PrimedPaul]

Pull Request Checklist

• I have read and followed the CONTRIBUTING.md guidelines.
• My contribution adds a new instruction, prompt, agent, skill, or workflow file in the correct directory.
• The file follows the required naming convention.
• The content is clearly structured and follows the example format.
• I have tested my instructions, prompt, agent, skill, or workflow with GitHub Copilot.
• I have run npm start and verified that README.md is up to date.

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Description

Adds the 'Oracle-to-PostgreSQL Migration Expert' Custom Agent, its associated skills, plugin manifest.
This custom agent is for helping users migrate application codebases from Oracle to Postgres.
This custom agent uses a 'gated' approach, never moving onto the next step without user approval.

The skills' syntax follow the 'Claude API Docs' best practices.

I constantly refine the custom agent by enhancing it's skillset with real-world occurrences of common migration errors and differences to look out for.

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Type of Contribution

• New instruction file.
• New prompt file.
• New agent file.
• New plugin.
• New skill file.
• New agentic workflow.
• Update to existing instruction, prompt, agent, plugin, skill, or workflow.
• Other (please specify):

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Additional Notes

I am currently working on an enterprise Oracle to Postgres migration exercise, converting legacy and modern application codebases. I created this custom agent to help the multiple developers on the team with instruction, guidance and achieving more consistent results.

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By submitting this pull request, I confirm that my contribution abides by the Code of Conduct and will be licensed under the MIT License.