feat(retrieval): 청킹/평가 하니스 + 검색 인덱스 개선

- src/retrieval/chunker.ts: 문서 청킹 로직 추가
- src/retrieval/evalHarness.ts + src/extension/evalCommands.ts: 검색 품질 평가 하니스
- brainIndex.ts / retrieval/index.ts / memoryContext.ts: 인덱싱·컨텍스트 빌더 개선
- config.ts / extension.ts / sidebarProvider.ts / package.json 갱신
- ADR-0030~0032 및 개발 기록, .astra 런타임 상태 동기화

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>

.astra/tests/stress/.astra/cache/21818066876cbf8515758bc351bb3d9d44f32b0e4cd024b2e055db3a0d34417e.json

@@ -1,5 +1,5 @@
 {
   "result": "Final report with inconsistencies. This should be long enough to pass validation.",
-  "createdAt": 1780367980792,
+  "createdAt": 1780882727041,
   "modelVersion": "unknown"
 }

.astra/tests/stress/.astra/cache/4fc755e372f1dd80d6bffc7b2ef973124fb64ba505f767c53a783833bbc3fa6a.json

@@ -1,5 +1,5 @@
 {
   "result": "Final report with inconsistencies. This should be long enough to pass validation.",
-  "createdAt": 1780367980791,
+  "createdAt": 1780882727039,
   "modelVersion": "unknown"
 }

.astra/tests/stress/.astra/cache/6e559207c4542d959700ff14f360e6575e54853929e991e579e318f2f5a19030.json

@@ -1,5 +1,5 @@
 {
   "result": "[{\"heading\":\"본문\",\"scope\":\"전체 답변\"}]",
-  "createdAt": 1780367980787,
+  "createdAt": 1780882727035,
   "modelVersion": "unknown"
 }

.astra/tests/stress/.astra/cache/f65136cebc95448a7e93a45745cb73b3a5a01af5d82391ec29a25bd72b8239a5.json

@@ -1,5 +1,5 @@
 {
   "result": "[CONFLICT WARNING] 성능이 200% 증가했습니다. vs 그러나 동시에 50% 감소했습니다. 최적화와 성능 저하가 동시에 발견됨.",
-  "createdAt": 1780367980789,
+  "createdAt": 1780882727037,
   "modelVersion": "unknown"
 }

.astra/tests/stress/.astra/missions/stress_conflict_1780882727018.json

@@ -1,8 +1,8 @@
 {
-  "missionId": "stress_conflict_1780367980767",
+  "missionId": "stress_conflict_1780882727018",
   "status": "completed",
-  "startTime": "2026-06-02T02:39:40.767Z",
-  "totalElapsedMs": 26,
+  "startTime": "2026-06-08T01:38:47.018Z",
+  "totalElapsedMs": 24,
   "results": {
     "outline": "[{\"heading\":\"본문\",\"scope\":\"전체 답변\"}]",
     "section_0": "[CONFLICT WARNING] 성능이 200% 증가했습니다. vs 그러나 동시에 50% 감소했습니다. 최적화와 성능 저하가 동시에 발견됨.",
@@ -14,30 +14,30 @@
     {
       "from": "idle",
       "to": "outline",
-      "durationMs": 19,
+      "durationMs": 15,
       "message": "답변 구조 잡는 중...",
-      "ts": "2026-06-02T02:39:40.786Z"
+      "ts": "2026-06-08T01:38:47.033Z"
     },
     {
       "from": "outline",
       "to": "section",
       "durationMs": 3,
       "message": "본문 작성 중...",
-      "ts": "2026-06-02T02:39:40.789Z"
+      "ts": "2026-06-08T01:38:47.036Z"
     },
     {
       "from": "section",
       "to": "polish",
-      "durationMs": 1,
+      "durationMs": 2,
       "message": "최종 다듬기 중...",
-      "ts": "2026-06-02T02:39:40.790Z"
+      "ts": "2026-06-08T01:38:47.038Z"
     },
     {
       "from": "polish",
       "to": "completed",
-      "durationMs": 2,
+      "durationMs": 4,
       "message": "미션 완료",
-      "ts": "2026-06-02T02:39:40.792Z"
+      "ts": "2026-06-08T01:38:47.042Z"
     }
   ],
   "resilienceMetrics": {