self-study-agent: self-driving loop, no memory format details, auto_repeat config

- Replace static pipeline diagram with self-driving loop (check memory → decide → execute → repeat)
- Remove detailed memory structure JSON schemas from all files
- Remove honcho-specific storage strategy from skill (storage is caller's responsibility)
- Add auto_repeat section to config.yaml (enabled, max_sessions_per_chat, stop_conditions)
- Add rule 8 (auto-repeat) and rule 9 (termination conditions) to execution rules
- Add session transition logic to adaptation.md (due cards → review, incomplete → study)

skills/self-study-agent/feedback/spaced-repetition.md

@@ -113,28 +113,4 @@ interval = max(min_interval, min(interval, max_interval))
          └── 카드 간격 업데이트
 ```
 
-## 메모리 저장 형식
-
-```json
-{
-  "cards": [
-    {
-      "id": "card_001",
-      "front": "...",
-      "back": "...",
-      "interval_days": 7,
-      "due_date": "2024-01-15",
-      "reps": 3,
-      "lapses": 0,
-      "stability": 2.5
-    }
-  ],
-  "stats": {
-    "total_cards": 100,
-    "due_today": 15,
-    "due_this_week": 45,
-    "overdue": 5,
-    "retention_rate": 0.88
-  }
-}
-```
+카드 데이터와 통계를 메모리에 저장합니다.