Preserve the cap64 stage transition before the larger run finishes

Constraint: The cap64 benchmark is still running, so only verified stage-transition evidence can be documented safely
Rejected: Wait for cap64 completion before checkpointing | Would leave the next session without proof that the run advanced from training into build-index
Confidence: high
Scope-risk: narrow
Directive: Keep recording cap64 milestones as they happen, but avoid updating winner guidance until report.json lands
Tested: Verified cap64 processes are active, confirmed the high_energy branch advanced from train.py to run_demo.py build-index on /tmp/ab_smoke_seg_cap64_top2/high_energy/fma/manifests, and confirmed report.json is still absent
Not-tested: Final cap64 scores, hybrid branch progression, and any post-cap64 strategy conclusion

+## 2026-06-02 cap64 进入 build-index checkpoint
+
+完成项：
+- 追加记录 cap64 benchmark 的阶段推进。
+- 已确认 `high_energy` 分支不再停留在训练，而是进入 `run_demo.py build-index`。
+
+验证证据：
+- 进程树显示：
+  - `scripts/ab_smoke_segmentation.py --work-root /tmp/ab_smoke_seg_cap64_top2`
+  - `external_adapters.py smoke-local ... /tmp/ab_smoke_seg_cap64_top2/high_energy`
+  - `run_demo.py build-index --data /tmp/ab_smoke_seg_cap64_top2/high_energy/fma/manifests ...`
+- 截至本 checkpoint：
+  - `cap64 report.json` 仍未生成
+
 ## 2026-06-02 cap64 benchmark 启动 checkpoint
 
 完成项：

@@ -60,5 +60,5 @@ test -f /tmp/ab_smoke_seg_cap48_top2_seed999/report.json && cat /tmp/ab_smoke_se
 ## 下一轮已启动
 
 - 新 benchmark：`/tmp/ab_smoke_seg_cap64_top2`
-- 当前阶段：`high_energy` 训练中
+- 当前阶段：`high_energy` build-index 中
 - 下一 session 应优先检查 `report.json` 是否生成

@@ -675,6 +675,6 @@ seed123 最终结论：
 - 已启动：`/tmp/ab_smoke_seg_cap64_top2`
 - 配置：`subset_size=64`, `max_test_queries=32`, `seed=42`
 - 当前最新证据：
-  - 已进入 `high_energy` 的 `train.py` 阶段
+  - 已从 `high_energy train.py` 推进到 `run_demo.py build-index`
   - 尚未产出最终 `report.json`