Fix mock provider entitlements and capability ordering

[blindzero]

Summary

• sort and deduplicate provider capability discovery while preserving expected inference order
• update the exported mock provider to include entitlement methods and advertised capabilities
• ensure provider contract tests import the test modules so the mock provider is available

Testing

• not run (PowerShell unavailable in the execution environment)

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Codex Task

[chatgpt-codex-connector]

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