refactor: narrow synchronous extension contracts

packages/core/agent/src/index.ts

@@ -228,7 +228,7 @@ export class AgentRegistry extends Service {
    *   Cordis effect disposer (single-shot): composite (generator) effects may
    *   yield it directly — exact identity nests the teardown in order.
    */
-  setFactory(factory: AgentFactory): () => Promise<void> | void {
+  setFactory(factory: AgentFactory): () => void {
     const dispose = this.ctx.effect(() => {
       if (this.factory !== undefined) throw new Error('an agent factory is already registered')
       // Avoid stacking two Cordis shadow layers when a caller passes a Service
@@ -242,6 +242,7 @@ export class AgentRegistry extends Service {
     // caller's composite effect can yield it for in-order teardown; the
     // loop's constructor effect returns it directly, identity-nesting the
     // registration under that effect.
+    // eslint-disable-next-line @typescript-eslint/no-misused-promises -- synchronous cleanup; direct return preserves disposer identity
     return dispose
   }
 
@@ -305,11 +306,12 @@ export class AgentRegistry extends Service {
    *   owner unload, unregistering the agent (and emitting `agent/disposed`)
    *   while its final turn is still draining.
    */
-  register(agent: Agent): () => Promise<void> | void {
+  register(agent: Agent): () => void {
     const dispose = this.ctx.effect(function* (this: AgentRegistry) {
       yield this.enter(agent)
       this.announce(agent)
     }.bind(this), 'agents.register()')
+    // eslint-disable-next-line @typescript-eslint/no-misused-promises -- synchronous cleanup; direct return preserves disposer identity
     return dispose
   }
 

packages/core/agent/src/types.ts

@@ -575,8 +575,7 @@ declare module 'cordis' {
      * returns `{ action: 'stop' }` to make this turn terminal, or `undefined`
      * to abstain. Terminal stop is monotonic: listener order and steering
      * cannot resume the turn, and pending steering is discarded rather than
-     * becoming another step or turn. A malformed non-undefined result fails
-     * the turn closed.
+     * becoming another step or turn.
      * @param agent - the agent whose composed continuation outcome may be stopped.
      * @param turn - the turn at its terminal-stop checkpoint.
      * Scope-filtered dispatch (`@deepseek-ai/dsh-scope`): a listener registered
@@ -586,7 +585,7 @@ declare module 'cordis' {
      * `scopeTarget`/`agentEvents`.
      * @mode serial
      */
-    'agent/turn-stop'(this: Scoped<Agent>, agent: Agent, turn: number): Promise<ContinuationStop | undefined> | ContinuationStop | undefined
+    'agent/turn-stop'(this: Scoped<Agent>, agent: Agent, turn: number): ContinuationStop | undefined
 
     // ---- error notifications (emit) ----
     /**