Define System Doc

Author exactly one Hybrid 1A catalog entry per invocation. Unfinished work stays under .skills/system-docs/<entry-key>/. Canonical consumer files are written only after explicit human approval of a structural validator-passing proposal.

Pack catalog SSOT (not installed into consumers): this skill directory's catalog/CATALOG.md and catalog/entries/.

Consult hooks in other skills: the shared rules live in consult-recipe.md (beside this file). Consumers point there; they do not restate them.

Resolve entry (bounded)

1. SKILL_DIR = directory containing this SKILL.md.
2. Read only SKILL_DIR/catalog/CATALOG.md; find the row for <entry-key>.
3. Load only the entry package path from that row (under SKILL_DIR/).
4. Load only template/validator paths named by the package (under SKILL_DIR/).
5. Do not load the full catalog body, every template, or the whole docs tree by default.