Re-baseline Layer 3 dogfood after major chain changes (perf re-eval)

[ZaxShen]

Why

docs/PERFORMANCE.md was retired in v0.1.2 — the load-bearing doctrine (target latency band + Tier 1/2/3 trim guidance + re-eval triggers) moved into CONTRIBUTING.md § Performance. Historical baseline + change-tracking now live in git history.

The doctrine includes re-evaluation triggers — this issue tracks the standing follow-up to re-baseline the Layer 3 dogfood timeline whenever any of those triggers fire, instead of carrying the dead-link doc forward.

Triggers (any of these → re-baseline + post timings here)

• A SWE-spawn or pr-reviewer-spawn cold-start in a Layer 3 dogfood takes >2× the previous baseline (current baseline: ~12min total at PR 🏛️ feat: Lego templates — plugin ships zero global agents #63, ~3-5 min target post-🚧 chore: latency reduction — proposals on review #64).
• A user reports a chain >12 min for a simple-triage task in real use.
• A new gate / hook / skill fires on the per-task path.
• CC platform changes subagent cold-start cost (model swap, tool-registration overhead, etc.).
• A new platform adapter (Codex / Cursor / OpenCode / Gemini CLI) lands — re-baseline on that platform.

How to re-baseline

1. Fresh claude --plugin-dir <PLUGIN_PATH> against a disposable scratch project.
2. Run scenario 2.1.bro from tests/manual/scenarios.md (@bro write a cli todo by python) and timestamp every ledger event.
3. Post the new timeline as a comment on this issue.
4. If the regression is real, open a focused fix-issue and link back.

Why an issue, not a doc

A doc invites scope creep ("while we're updating perf, let me add this other note"). A perf issue is closed-when-fixed and reopens when the next regression hits. Doctrine is durable (CONTRIBUTING); measurements are ephemeral (issues + git).

[ZaxShen]

Issue tracking moved to Linear. This issue continues as TRU-15: https://linear.app/trustmybot/issue/TRU-15

GitHub issues are no longer the active tracker for this project — see the Linear workspace for current state. Closed-as-migrated, not closed-as-resolved.

[ZaxShen]

Disregard the prior 'closed-as-migrated' comment. GitHub remains the public issue tracker for this project — file new issues, PRs, and discussion here as normal. TMB team mirrors this issue internally to Linear (TRU-15) for our own workflow, but that mirror is auto-synced from GitHub — contributors don't need a Linear account.

[ZaxShen]

Closing — focusing on v0.8.x. Planning lives on GitLab milestones (v0.8.0 / v0.8.1). Will re-mirror active items to GH once tri-source schema sync (#48) lands.