AppSeedStore

The app template, over `Settings` custom settings (§SS-6.4).

In the namespace construct::settings. Declared in src/libs/libconstruct/construct/settings/AppSeedStore.hpp.

Detailed description

Answers exactly one question: *what should a new scene, or a new camera, start with?* It is copied at creation and then unlinked (§SS-7.1), which is why `config::Resolver` refuses to accept it as a chain member — if a preference could parent an open document, the same `.construct` would render differently on the author's machine and the farm's (§SS-7.2).

The store is registered with the resolver via setSeedStore() so the two copy verbs can read and write it without it ever being resolved through.