Compose explicit owners
A composition app explicitly selects packages with uses=[...] and imports explicitly exported named declarations with use owner {Name}; bound imports add from=deployment.name for remote interfaces. Composition does not copy or retag another package's source, identity, authority, or storage. Imports resolve to declared members; visibility alone grants no call or read permission. Use a package's canonical operations for cross-package mutation, rather than writing its model directly.
Choose one implicit app for a small standalone system. Split into packages when ownership is genuinely separable and compose them explicitly. Shared defaults and context resources have one owner; avoid shadow configurations that make runtime identity ambiguous. See source syntax for layout and the syntax reference for exact composition forms.