Track PR #259: Declare CoderForge file editor tool metadata

[neubig]

Tracks #259.

This PR declares the str_replace_editor tool metadata for CoderForge standardized trajectories so existing SDK conversion can initialize the file editor tool.

This issue was created by an AI agent (OpenHands) on behalf of Graham Neubig.

PR evidence acceptance criteria

• Current main evidence: Standardize a CoderForge trajectory containing str_replace_editor on current main and capture the missing editor-tool metadata or SDK initialization failure.
• PR branch evidence: On PR Declare CoderForge file editor tool metadata #259, standardize the identical trajectory, verify the declared metadata initializes the file editor, executes a representative replacement, and round-trips without altering unrelated tools.
• Required evidence package: The PR records both commit SHAs and exact environment/setup. Run the full relevant backend, service, infrastructure, or data pipeline live with PR code and attach commands plus output/logs; a movie or video is not a substitute for this live run. Attach sanitized input/output trajectory excerpts, converter command, SDK tool-init/invocation logs, and tests.