fix(agents): raise compaction threshold to 160K (80% of 200K limit)

80K was too aggressive and caused premature context loss. Now triggers
at 160K tokens with a target of 80K after compaction.

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

packages/services/conversation-service/src/infrastructure/agents/types/context.types.ts

@@ -190,8 +190,8 @@ export interface ContextInjectorConfig {
 export const DEFAULT_CONTEXT_CONFIG: ContextInjectorConfig = {
   maxContextTokens: 4000,
   enableAutoCompaction: true,
-  compactionThreshold: 80000,
-  compactionTarget: 40000,
+  compactionThreshold: 160000,
+  compactionTarget: 80000,
   enabledContextTypes: Object.values(ContextType),
 };