- Include `--timing-json` on broad or flaky runs when command duration or sync

behavior matters.

Before/after PR proof on delegated Testbox:

- For PRs that should prove "broken before, fixed after", compare base and PR

on the same Testbox when practical. Fetch both refs, create detached temp

worktrees under `/tmp`, install in each, then run the same harness twice.

- Do not checkout base/PR refs in the synced repo root. Delegated Testbox sync

may leave the root dirty with local files; `git checkout` can abort or mix

proof state.

- Temp harness files under `/tmp` do not resolve repo packages by default. Put

the harness inside the worktree, or in ESM use

`createRequire(path.join(process.cwd(), "package.json"))` before requiring

workspace deps such as `@lydell/node-pty`.

- For full-screen TUI/CLI bugs, a PTY harness is stronger than helper-only

assertions. Use a real PTY, wait for visible lifecycle markers, send input,

then send control keys and assert process exit/stuck behavior.

- When validating a rebased local branch before push, remember delegated sync

usually validates synced file content on a detached dirty checkout, not a

remote commit object. Record the local head SHA, changed files, Testbox id,

and final success markers; after pushing, ensure the pushed SHA has the same

file content.

- If GitHub CI is still queued but the exact changed content passed Testbox

`pnpm check:changed`, `pnpm check:test-types`, and the real E2E proof, it is

reasonable to merge once required checks allow it. Note any still-running

unrelated shards in the proof comment instead of waiting forever.

Interactive CLI/onboarding:

- For full-screen or prompt-heavy CLI flows, run the target command inside tmux