feat(framework): show tool call cwd on Braintrust tool spans

[Coly010]

Current Behavior

#356 records the working directory of each tool call on ToolCallRecord, but it stops there. The Braintrust upload builds tool spans from transcript parts, which carry no cwd, so a trace can't show which project a supabase start or supabase stop ran in. This was requested in the #356 review.

Expected Behavior

Tool-call transcript parts carry an optional cwd, copied from the event's tool.cwd in adaptTranscript. The upload's transcript schema accepts it and tool spans log it as metadata.cwd next to tool_name. The key is left off when the agent didn't record a directory. Results written before this change still parse.

Test plan

• adaptTranscript sets cwd on the transcript part only when the event has tool.cwd
• Transcript schema parses parts with and without cwd
• logTranscript puts cwd in tool span metadata when present and omits it otherwise
• pnpm format:check, pnpm typecheck
• core, framework, sandbox, web tests and test:cli-lib
• pnpm check end to end (the judge smoke step needs a provider key)

🤖 Generated with Claude Code

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1 Skipped Deployment

Project	Deployment	Actions	Updated
evals	Ignored	Preview	Oct 7, 2026 11:51am UTC

[Rodriguespn]

Confirm I can see the cwd in the eval metadata (BT trace).

Approving this. Thanks @Coly010 🙌