Placemats

Principles define what must hold. Checks are deterministic, standalone scripts that report specific violations. Lenses collect review disciplines and the checks that enforce them. Skills are on-demand agent procedures. Surfaces expose a shared internal API over transports. These categories have different responsibilities and should not be collapsed into one generic idea of a framework or methodology.

Construction: Is the implementation built correctly? This includes import direction, forbidden cycles, and required structural boundaries. Construction can pass even when the wrong capability was built.

Surfaces translate and render. The API coordinates the operation and is the shared entry point. The library implements the work. Dependencies flow down from surfaces through API to library; peer API submodules are kept independent. A feature vertical can co-locate its library, API, and surface adapters without dissolving these dependency rules.

State is classified by its persistence contract rather than by a convenient folder name. Some state ships with a release and admits no runtime writer; some changes only through an administrator's deliberate act; some is accumulated by the running system. Packaging, configuration, upgrade, and deployment should honor those distinctions so generated or operational state does not masquerade as committed source.