build-log

维护写一次性的构建日志条目，记录阶段完成与门控结果的数值证据。

维护一个写一次的构建日志目录，用编号条目记录阶段完成和门控结果，并附上数值证据。只有在阶段性完成或某个 sanity-gate 成为永久证据时才写，门槛高，不会为小改动建条目。它的价值在于成为可引用的方法记录和项目的长期回放记忆，每条都要有能被引用的实证数据。

# build-log

Maintain `{{build_log_dir}}` as a write-once series of numbered entries
(`NN_kebab_topic.md`) recording phase completions and gate results *with their numerical
evidence*. The build log is the raw "methods" material for the eventual paper and the
project's replay memory after long gaps — every entry must be worth citing in one of those
two roles.

## When to use

The threshold is deliberately high. Open an entry only for:

- **Phase completion** — all of a phase's modules and tests green, gate passed.
- **Fixing a gate result** — a correctness-gate tolerance update, a first successful
  end-to-end run of new machinery, a first result curve.
- **Documenting a decision's implement