A preset page baked only the instance's props, so every default in the profile's
.meta.json config that the instance did not repeat was lost (go-int: upg-neighbor's
five presets dropped pinHint:false). instanceHtml now takes the meta config first
and the props over it. check:preset-config-merge (gates:post) reads every built
preset page and fails on a lost default; the rule is written into
PRESET-PLUGIN-STANDARD.md. Affected before the fix: upg-neighbor only; no
production preset has profile defaults to lose.
generate-tree derives each profile's tier from its composes edges (composing
anything is capability 4; composing a capability-4 plugin is capability 5). An
explicit type is checked against the derivation and a contradiction fails the
build naming both. check:capability-derived asserts every profile is 1-5 and
agrees. documentation/PRESET-PLUGIN-STANDARD.md describes the one
*.instances.json file a preset plugin declares.
