feat: 리밸런싱 엔진 V1 + GAS 버그 수정 (2026-06-13)

주요 변경:
- tools/build_rebalance_engine_v1.py: REBALANCE_ENGINE_V1 신규
  * account_snapshot 직접 합산(_build_snap_position_map) → 소수주 분리 행 병합
  * 레짐 소스 macro.REGIME_PRELIM 최우선 (GAS 와 동일)
- src/gas_adapter_parts/gdf_06_rebalance.gs: runRebalanceSheet_() 신규
  * Logger.log / getSpreadsheet_() 로 run_all 연동 수정
- src/gas_adapter_parts/gdc_01_fetch_fundamentals.gs
  * _mergePositionRecord_(): 소수주 중복 행 합산 신규
  * parseInt → parseFloat (qty, availQty)
- src/gas_adapter_parts/gdf_01_price_metrics.gs
  * 미보유 종목 SELL_READY → WATCH_EXIT_SIGNAL
- spec/41_release_dag.yaml: build_rebalance_sheet 노드 추가 (step_count 63)
- spec/51_formula_lifecycle_registry.yaml: REBALANCE_ENGINE_V1 등록

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

governance/adr_index.yaml

@@ -0,0 +1,44 @@
+schema_version: adr_index.v1
+adr_count: 10
+entries:
+  - adr_id: ADR-0001
+    title: Adopt active artifact manifest
+    status: accepted
+    path: governance/adr/0001-adopt-active-artifact-manifest.md
+  - adr_id: ADR-0002
+    title: Adopt authority matrix
+    status: accepted
+    path: governance/adr/0002-authority-matrix.md
+  - adr_id: ADR-0003
+    title: Freeze baseline metrics
+    status: accepted
+    path: governance/adr/0003-baseline-metrics.md
+  - adr_id: ADR-0004
+    title: Introduce rule lifecycle policy
+    status: accepted
+    path: governance/adr/0004-rule-lifecycle.md
+  - adr_id: ADR-0005
+    title: Split formula registry by domain
+    status: accepted
+    path: governance/adr/0005-formula-domain-split.md
+  - adr_id: ADR-0006
+    title: Make final decision packet canonical
+    status: accepted
+    path: governance/adr/0006-final-decision-packet.md
+  - adr_id: ADR-0007
+    title: Mandatory shadow ledger
+    status: accepted
+    path: governance/adr/0007-shadow-ledger.md
+  - adr_id: ADR-0008
+    title: Low capability renderer contract
+    status: accepted
+    path: governance/adr/0008-renderer-contract.md
+  - adr_id: ADR-0009
+    title: Number provenance audit
+    status: accepted
+    path: governance/adr/0009-number-provenance.md
+  - adr_id: ADR-0010
+    title: Change request template
+    status: accepted
+    path: governance/adr/0010-change-request-template.md
+