refactor: remove dcp_for_compaction and preemptive_compaction features

- Delete src/hooks/preemptive-compaction/ entirely
- Remove dcp_for_compaction from schema and executor
- Clean up related imports, options, and test code
- Update READMEs to remove experimental options docs

src/hooks/index.ts

@@ -8,7 +8,7 @@ export { createDirectoryAgentsInjectorHook } from "./directory-agents-injector";
 export { createDirectoryReadmeInjectorHook } from "./directory-readme-injector";
 export { createEmptyTaskResponseDetectorHook } from "./empty-task-response-detector";
 export { createAnthropicContextWindowLimitRecoveryHook, type AnthropicContextWindowLimitRecoveryOptions } from "./anthropic-context-window-limit-recovery";
-export { createPreemptiveCompactionHook, type PreemptiveCompactionOptions, type SummarizeContext, type BeforeSummarizeCallback } from "./preemptive-compaction";
+
 export { createCompactionContextInjector } from "./compaction-context-injector";
 export { createThinkModeHook } from "./think-mode";
 export { createClaudeCodeHooksHook } from "./claude-code-hooks";