v2.1.2 — correctness patch (self-audit)

Small correctness fixes found by auditing the tool against its own author's production brain. Backward compatible — no format changes, no new required fields.

Fixed

• People changes now count as compact drift — data_lines() stripped every @ line as metadata, but @people / @ <slug> lines are data; editing # People never triggered the "index.compact is out of date" warning. Regression test added.
• brain-nudge no longer nudges right after a save — it fires only when a change is newer than index.md, not on a merely-dirty git tree.
• HOT tiering counts the resume line — recency is now max(topic dates, resume date), so an actively-worked project keeps its HOT slot.
• [inactive …] no longer parses as active — status matching uses word boundaries.
• --diff no longer mislabels archived topics as project _archive; archived material is excluded from the changed-since view.
• brain-compact counted only WARM projects in its summary line (P missed P+).

Added

• brain-check prints its own version in the summary — a stale install (repo updated, install.sh not re-run) is now visible instead of silently mis-validating.
• Wider export redaction: emails / ssh targets (user@host), IPv6, and a much broader TLD list (.pl, .cz, .fr, .online, …).

Full details in CHANGELOG.md.