refactor: apply repository naming contract

Apply the accepted pre-release package, service, type, directory, and role renames as one repository-wide change.

packages/core/session/tests/fork.spec.ts

@@ -7,7 +7,7 @@ import type { SessionEvent, TurnEndReason } from '@deepseek-ai/dsh-session'
 declare module '@deepseek-ai/dsh-session/types' {
   interface SessionEventMap {
     'test/log-only': { value: string }
-    /** Stands in for a plugin's open/close bracket (`compact/start`). */
+    /** Stands in for a plugin's open/close bracket (`compaction/start`). */
     'test/bracket-open': { id: string }
   }
 }