fix(mcpserver): omit pydantic auto-derived titles on tool input schemas

[ktz03]

Summary

• Add ToolInputJsonSchema that suppresses pydantic auto-derived field titles via field_title_should_be_set.
• Use it for Tool.from_function input model_json_schema generation.
• Keep explicit Field(title=...) / WithJsonSchema titles; leave output-schema generation unchanged for a smaller blast radius.

Fixes #3391

Test plan

• New unit tests: auto titles omitted; explicit Field(title=...) kept
• Existing mcpserver tool / docs snapshot tests — may need expectation updates where they asserted auto titles on input properties

[github-actions]

This PR has been closed automatically. This repo only keeps pull requests open when they come from a maintainer, or from a contributor a maintainer has assigned to the linked issue, and you aren't currently assigned to #3391.

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• We're a small team with very little capacity to review community PRs right now.
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Maintainers: reopen, remove missing-issue-link, or add bypass-issue-check to override.