feat(engine): implement self-reflection (reflector) stage in multi-agent pipeline

- Added ReflectorAgent for meta-cognition and critical review between Research and Writing
- Updated WriterAgent to explicitly address reflection critiques
- Introduced 'g1nation.enableReflection' configuration setting
- Added comprehensive integration tests for the self-reflection stage
- Documented design decisions in ADR-0010 and related discussion records

src/agents/AgentWorkflowManager.ts

@@ -1,5 +1,6 @@
-import { PlannerAgent, ResearcherAgent, WriterAgent } from './factory';
-import { AgentEngine, PipelineStage } from '../lib/engine';
+import { PlannerAgent, ResearcherAgent, ReflectorAgent, WriterAgent } from './factory';
+import { AgentEngine, PipelineStage, AgentExecuteOptions } from '../lib/engine';
+import { getConfig } from '../config';
 
 export class AgentWorkflowManager {
     /**
@@ -15,9 +16,16 @@ export class AgentWorkflowManager {
         const planner = new PlannerAgent(modelName);
         const researcher = new ResearcherAgent(modelName);
         const writer = new WriterAgent(modelName);
-        const engine = new AgentEngine(planner, researcher, writer);
+        // [Self-Reflection] 설정으로 비활성화하지 않은 경우에만 Reflector를 주입.
+        const enableReflection = getConfig().enableReflection !== false;
+        const reflector = enableReflection ? new ReflectorAgent(modelName) : undefined;
+        const engine = new AgentEngine(planner, researcher, writer, reflector);
         const missionId = `mission_${Date.now()}`;
 
+        const runOptions: AgentExecuteOptions = {
+            config: { enableReflection }
+        };
+
         try {
             return await engine.runMission(
                 missionId,
@@ -26,7 +34,8 @@ export class AgentWorkflowManager {
                 signal,
                 (stage: PipelineStage, message: string) => {
                     onProgress(this.mapStageToUI(stage), message);
-                }
+                },
+                runOptions
             );
         } catch (error: any) {
             if (error.name === 'AbortError' || error.message.includes('cancelled')) {
@@ -41,6 +50,7 @@ export class AgentWorkflowManager {
             idle: '대기',
             planner: 'Planner',
             researcher: 'Researcher',
+            reflector: 'Reflector',
             writer: 'Writer',
             completed: '완료',
             error: '오류'