# Runtime Guidance
- The runtime interprets frozen IR and adapts abstract operations to substrate
interfaces. It must not redefine core identities or transition laws.
- `PluginHost` is the authority boundary for external execution. A manifest is a
capability advertisement, not authorization.
- Every plugin call pins an immutable occurrence binding before execution.
- Reusable definition calls create a distinct deterministic invocation identity,
receive only their explicit input, and return only their declared result.
They do not inherit caller locals or imply a new transactional scope.
- Mutating effects remain staged until scope commit unless an explicit release
policy says otherwise. Dispatch ambiguity must be recorded as `unknown` before
reconciliation.
- `PrepareEffect` may be repeated after response loss with the same structural
intent ID and input. A plugin must make that prepare idempotent and must not
interpret the repeat as a new world mutation.
- Keep the reference runtime synchronous and dependency-light. Production async,
durable, and distributed realizations should be separate adapters.