chore(changeset): raise @objectstack/lint to minor — a Clause-② yes declaration takes at least minor

AGENTS.md: "The declaration is `Clause-②: yes|no` plus at most one arm from the
closed pair `(widening)`/`(narrowing)`: `yes` takes at least `minor`".

This PR declares `Clause-②: yes` — the acceptance set widens, as a precision
fix to an advisory rule — so `patch` was below the floor.

Co-authored-by: Claude <noreply@anthropic.com>

Author: claude

.changeset/17135-field-consumers-synthesized-layout.md

@@ -1,5 +1,5 @@
 ---
-"@objectstack/lint": patch
+"@objectstack/lint": minor
 ---
 
 `field-no-consumers` now reads two consumers that name the field nowhere in metadata — a declared field group placing it on the synthesized layout, and the column a seed or import mapping matches on (#17135).