fix(schedule): follow latest session and chat contracts

packages/schedule/tool-schedule/src/types.ts

@@ -4,7 +4,7 @@
  */
 
 import type { Branded } from '@deepseek-ai/dsh-brand'
-import type {} from '@deepseek-ai/dsh-session'
+import type {} from '@deepseek-ai/dsh-session/types'
 
 /** Stable reminder identity that is unique and never reused within one session. */
 export type ScheduleId = Branded<'ScheduleId'>
@@ -135,7 +135,7 @@ export type ScheduleDeleteResult =
 /** Canonical `schedule_delete` value. */
 export type ScheduleDeleteValue = ScheduleDeleteResult | ScheduleToolError
 
-declare module '@deepseek-ai/dsh-session' {
+declare module '@deepseek-ai/dsh-session/types' {
   interface SessionEventMap {
     /**
      * Versioned Schedule mutation. The owning package validates the complete