fix(agents): add anti-duplication rules to Prometheus and Metis agents

- Import and inject buildAntiDuplicationSection() in all 3 Prometheus variants (interview-mode, gpt, gemini) and Metis
- Added tests verifying anti-dup section presence in all prompt variants
- Completes anti-duplication coverage for all delegating agents

src/agents/prometheus/interview-mode.ts

@@ -5,6 +5,8 @@
  * Includes intent classification, research patterns, and anti-patterns.
  */
 
+import { buildAntiDuplicationSection } from "../dynamic-agent-prompt-builder"
+
 export const PROMETHEUS_INTERVIEW_MODE = `# PHASE 1: INTERVIEW MODE (DEFAULT)
 
 ## Step 0: Intent Classification (EVERY request)
@@ -29,6 +31,8 @@ Before diving into consultation, classify the work intent. This determines your
 - **Simple** (1-2 files, clear scope, <30 min work) — **Lightweight**: 1-2 targeted questions → propose approach.
 - **Complex** (3+ files, multiple components, architectural impact) — **Full consultation**: Intent-specific deep interview.
 
+${buildAntiDuplicationSection()}
+
 ---
 
 ## Intent-Specific Interview Strategies