feat: add lsp_format_document tool

[Dhirenderchoudhary]

Description

Adds an agent-callable lsp_format_document tool that uses the existing LSPManager.formatDocument() API to format a file via the connected language server, apply the returned edits, and write the result to disk. This replaces the need to guess a formatter CLI through execute_bash.

Also wires approval, plan-mode exclusion, ACP tool kind, compact result display, and a short docs note.

Closes #1171

Type of Change

• Bug fix
• New feature
• Breaking change
• Documentation update

Changeset

• Added a changeset (pnpm changeset) describing this change for the changelog

Docs-only or internal chores need no changeset (or run pnpm changeset --empty to note that intentionally).

Testing

Automated Tests

• New features include passing tests in .spec.ts/tsx files
• All existing tests pass (pnpm test:all completes successfully)
• Tests cover both success and error scenarios

Manual Testing

• Tested with Ollama
• Tested with OpenRouter
• Tested with OpenAI-compatible API
• Tested MCP integration (if applicable)

Checklist

• If this was for an open issue, I was assigned to it
• Code follows project style guidelines
• Self-review completed
• Documentation updated (if needed)
• No breaking changes (or clearly documented)
• Appropriate logging added using structured logging (see CONTRIBUTING.md)

[github-actions]

No changeset found

This PR does not add a changeset, so it will not appear in the changelog or trigger a release.

If the change is user-facing, add one:

pnpm changeset

Pick a bump (patch / minor / major) and write the changelog entry in our usual voice ("Added X... Thanks to @you. Closes #123."), then commit the generated .changeset/*.md file.

If this PR is docs-only or a chore that needs no release note, you can ignore this - or run pnpm changeset --empty to record that intentionally.