resolve() layers open overlays onto canonical pages (overlay_state=DRAFT always
surfaced; overlaid body projected when policy.show_drafts); draft-only edits make
a not-yet-existing page resolvable. Never hides an unapplied overlay (I-4). Policy
gains show_drafts. 4 tests green, pyflakes clean.
Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>
