Feat/resolve review threads

[plwalters]

Summary

Adds resolve_thread and unresolve_thread methods to the pull_request_review_write tool, enabling users to resolve and unresolve PR review threads via GraphQL mutations.

Why

Fixes #1768

What changed

• Added ThreadID field to PullRequestReviewWriteParams struct
• Added threadId parameter and new methods to tool schema
• Implemented ResolveReviewThread function using GraphQL resolveReviewThread and unresolveReviewThread mutations
• Added switch cases for resolve_thread and unresolve_thread methods
• Added unit tests covering success and error scenarios
• Updated toolsnaps and generated docs

MCP impact

• No tool or API changes
• Tool schema or behavior changed — Added two new methods (resolve_thread, unresolve_thread) and a new threadId parameter to the existing pull_request_review_write tool.
• New tool added

Prompts tested (tool changes only)

• "Resolve the review thread PRRT_kwDOxxx on PR Issue: Fix incorrect VS Code installation URL (both buttons point to Insiders) #123"
• "Unresolve the feedback thread on this pull request"
• "Mark the review comment thread as resolved"

Security / limits

• No security or limits impact — Uses existing GraphQL client authentication; thread resolution is already permission-controlled by GitHub.
• Auth / permissions considered
• Data exposure, filtering, or token/size limits considered

Tool renaming

• I am renaming tools as part of this PR (e.g. a part of a consolidation effort)
  • I have added the new tool aliases in deprecated_tool_aliases.go
• I am not renaming tools as part of this PR

Note: if you're renaming tools, you must add the tool aliases. For more information on how to do so, please refer to the official docs.

Lint & tests

• Linted locally with ./script/lint
• Tested locally with ./script/test

Docs

• Not needed
• Updated (README / docs / examples) — Auto-generated via script/generate-docs