mkbackend-development

# Backend Development Coordinates a backend change end to end. It routes; it does not absorb the specialists. ## Ownership | Owner | Owns | Does NOT own | |---|---|---| | `mk:api-design-principles` | Interface contract: resource/type/message shape, error and authorization *requirements*, compatibility and deprecation, consumer discovery | Implementation, persistence, security verdict, release | | `mk:backend-development` | End-to-end backend change: discovery, classification, service/handler/integration work, wiring the specialists together | Contract authorship, schema/SQL, security verdict, deploy | | `mk:database` | Data invariants, schema, migration and recovery, query/index evidence, ORM boundary | API contract, authorization verdict, infrastructure execution | | `mk:devops` | Infrastructure-as-code, containers, CI, runtime config, deployment safety design, rollback, incident diagnosis | Deploy approval and execution, security verdict, code root-cause, schema semantics | Routing rules — identical in all four skills: - **Contract-only API question → `mk:api-design-principles`**, even in the middle of a task owned by another skill. "Contract" means what a consumer can observe: field set, error shape, status semantics, pagination, versioning. Extending an endpoint without changing any of those is not a contract change. - **End-to-end backend change → `mk:backend-development`**, which invokes the API skill only when a new, public, or breaking contract is in scop...