chore: Remove TASK3_TRACEABILITY_RESULTS.md and update roadmap

- Deleted docs/TASK3_TRACEABILITY_RESULTS.md (temporary test results file)

- Updated PHILOSOPHY.md: Stage 2 marked as COMPLETED

- Added Post-Stage 2 Enhancements section documenting Task 1, 2, 3 completion

Author: anhmtk

docs/PHILOSOPHY.md

@@ -98,7 +98,7 @@ StillMe is explicitly designed to:
 - Retention metrics for quality assessment
 - **Result:** AI knows what it knows (self-assessment capability)
 
-**Stage 2: Meta-Learning (v0.7) 🚧 IN PROGRESS**
+**Stage 2: Meta-Learning (v0.7) ✅ COMPLETED**
 - ✅ **Phase 1: Retention Tracking** (COMPLETED)
   - Document usage tracking
   - Retention metrics calculation
@@ -119,6 +119,30 @@ StillMe is explicitly designed to:
 - **Goal:** AI improves HOW it learns (not what it learns)
 - **Timeline:** All 3 phases completed! ✅
 
+**Post-Stage 2 Enhancements (v0.7.1) ✅ COMPLETED**
+- ✅ **Task 1: Meta-Learning Dashboard** (COMPLETED)
+  - Integrated into existing Learning page as new tab
+  - 3 sub-tabs: Retention Tracking, Curriculum Learning, Strategy Optimization
+  - Visualizations: Plotly charts for source retention rates, learning effectiveness, strategy performance
+  - Real-time metrics display with pandas dataframes
+  - Status: Tested and operational on production
+  
+- ✅ **Task 2: Response Caching Enhancement** (COMPLETED)
+  - Validation result caching to reduce redundant LLM calls
+  - Smart cache key generation (query hash + context hash)
+  - Redis backend with in-memory fallback
+  - TTL management (24 hours default)
+  - Expected savings: 20-30% cost reduction for repeated/similar queries
+  - Status: Tested and operational on production
+  
+- ✅ **Task 3: Request Traceability** (COMPLETED)
+  - Full request trace from API → RAG → LLM → Validation → Response
+  - Unique trace ID per request (correlation ID)
+  - Trace storage: Redis with in-memory fallback (24h TTL)
+  - API endpoint: GET `/api/trace/{trace_id}` for full trace retrieval
+  - Metadata captured: query, duration, confidence, validation status, epistemic state
+  - Status: Tested and operational on production (test response time: ~3s)
+
 **Stage 3: Bounded Autonomy (v1.0) 🔬 RESEARCH PHASE**
 - Limited self-optimization within safety constraints
 - Human-approved architectural changes only