docs(maintain): read reconcile's mechanical_count before a large drift report's findings

[catincloudlabs]

What this changes

#544, as claimed on the issue. One bullet opens the maintain skill's Reconcile proposals section:

On a large check report, read the ratio before the findings. Run maintain reconcile and read mechanical_count and advisory_count beside the finding codes, before the findings list. Mechanical proposals exist only where dex can author the fix itself (the two cases below), so zero of them across hundreds of schema findings, with no column_dropped, column_retyped or table_dropped among the codes, usually means the baseline is behind the project rather than the warehouse having moved: every finding is additive, and most of them are the project's own recent work. Re-baseline with the discipline above (explore map --full, then maintain snapshot) before triaging findings one by one. A type change is advisory on every format, so read the codes for retypes rather than inferring them from the count.

Phrased against reconcile's current semantics: the two mechanical cases are the ones the next bullet already names (a dex-scaffolded staging model re-scaffolded, or drifted columns edited into a declaration, the second being what #429 added), and the type-change sentence is there because the section already says a retype is advisory on every format, so a reader cannot infer "no retypes" from a zero mechanical count.

Where it sits, and where it does not

• In Reconcile proposals, the section the issue named first, because a reader triaging a large check arrives there from step 4 of the procedure. The alternative placement, the check step itself, would put a paragraph inside the procedure block the three skills hold in common (test_the_three_procedure_sections_are_one_text), which is not this change's to widen.
• It cites the re-baseline discipline the skill already states under The baseline, rather than restating it.
• Documentation only. No engine, no tests, no envelope.

Checks run

uv run pytest -q tests/test_skill_bodies.py tests/test_docs_policy.py   19 passed

No em dash in the file (the em-dashes job), and the procedure block is untouched.

Files

• skills/maintain/SKILL.md: the bullet.
• CHANGELOG.md: one Changed entry under Unreleased.

This touches the same file as #534 (the description, in the frontmatter) in a different region; whichever merges second rebases cleanly.

🤖 Generated with Claude Code