0744 — Controllers keep dependencies and registration owns declarations

Context

0742 assembled per-stream provisioners by rebuilding a StreamController during registration. Stream and system controllers stored declarers in their constructors, unlike other domain controllers. Worker declarations also bypassed RegisterWorker because its sparse config changed an explicit zero target into one.

Decision

Revise 0742 in registration assembly and initial-target handling; retain the maintenance operations and the deferrals in 0743.

StreamController and SystemController constructors take only their datastore and logger. Their registration methods register their own resources. Admin reuses those controllers and declares the workers afterward, preserving the existing order and partial-failure behavior. Fixed system declarers belong to admin; stream-specific provisioners are assembled from that call’s config, as the metrics collector already is. No shared controller is reconfigured.

RegisterWorker takes initialTarget as an explicit required InstanceTarget. WorkerConfig holds optional metadata only. DeclareWorker checks definition ownership, then uses RegisterWorker’s shared validation and persistence path. Zero starts a new worker suspended; registration never overwrites an existing operational target. Consumer declarations explicitly keep NoInstanceTarget.

Consequences

Other controller constructors already hold long-lived dependencies and need no corresponding change. The supported client API is unchanged. Advanced callers of the two constructors and RegisterWorker must adapt their calls. Database writes and their ordering are unchanged; a failed declaration still returns an error and can be retried by registering again. No schema change.