Address feedback on MCPModelClass shutdown lifecycle

[Copilot]

Why

• Clarify when shutdown() is called in the MCP model lifecycle in response to reviewer question.

How

• Answered reviewer question about shutdown() method invocation timing:
  • Called automatically via __del__() during garbage collection
  • Can be called manually by users for explicit cleanup
  • Triggers _background_shutdown() which closes stdio client then parent resources
  • Additionally handled by lifespan context manager's finally block

Tests

• No code changes required - question answered with explanation of existing behavior.

Notes

• This is a follow-up to PR [PR-1092][PR-1093] Optimised MCPModelClass and supports for Sdtio MCP servers #872 addressing review comment [PR-1092][PR-1093] Optimised MCPModelClass and supports for Sdtio MCP servers #872 (comment)

---

💬 We'd love your input! Share your thoughts on Copilot coding agent in our 2 minute survey.

[github-actions]

Package	Line Rate	Health
clarifai	45%	❌
clarifai.cli	58%	➖
clarifai.cli.templates	46%	❌
clarifai.client	67%	➖
clarifai.client.auth	67%	➖
clarifai.constants	100%	✔
clarifai.datasets	100%	✔
clarifai.datasets.export	80%	✔
clarifai.datasets.upload	75%	➖
clarifai.datasets.upload.loaders	37%	❌
clarifai.models	100%	✔
clarifai.modules	0%	❌
clarifai.rag	0%	❌
clarifai.runners	53%	➖
clarifai.runners.models	56%	➖
clarifai.runners.pipeline_steps	41%	❌
clarifai.runners.pipelines	77%	➖
clarifai.runners.utils	62%	➖
clarifai.runners.utils.data_types	72%	➖
clarifai.schema	100%	✔
clarifai.urls	60%	➖
clarifai.utils	60%	➖
clarifai.utils.evaluation	67%	➖
clarifai.workflows	95%	✔
Summary	61% (8702 / 14210)	➖

Minimum allowed line rate is 50%