Implements the operation context types in registry/context.rs (ADR-015,
ADR-022, ADR-024): OperationContext with all 10 fields (internal is
pub(crate) for writes, read via is_internal()), AbortPolicy enum with
AbortDependents default, CompositionAuthority with synthetic Identity
projection for ACL, ScopedOperationEnv reachability set, and
generate_request_id() (UUID v4). Adds a minimal OperationEnv trait
forward-declaration in registry/env.rs so the context env field compiles;
the operation-env task will expand it.
glm-5.2
3b9c480dad