Add a repo status snapshot for faster session handoff

Constraint: Future sessions need a quick machine-readable summary of the verified repo state and next commands
Rejected: Depend on manual reconstruction from docs and git history alone | Slower and more error-prone during handoff
Confidence: high
Scope-risk: narrow
Directive: Keep the snapshot script aligned with the real default docs, drop zones, smoke outputs, and next-step commands
Tested: /usr/local/miniconda3/bin/python scripts/status_snapshot.py
Not-tested: Consumption of the snapshot by external automation beyond manual review

@@ -10,6 +10,7 @@ Use this checklist when a new session starts working on the repo.
 ## 2. Verify repo health
 ```bash
 git status --short
+/usr/local/miniconda3/bin/python scripts/status_snapshot.py
 ```
 
 ## 3. Verify open-dataset tooling

+#!/usr/bin/env python3
+import json
+import subprocess
+from pathlib import Path
+
+root = Path.cwd()
+workspace_root = root.parent
+
+def sh(cmd):
+    return subprocess.check_output(cmd, shell=True, text=True).strip()
+
+snapshot = {
+    'latest_commit': sh('git log --oneline -n 1'),
+    'docs': {
+        'readme': str((workspace_root / 'docs/README.md').resolve()),
+        'handoff': str((workspace_root / 'docs/session-handoff.md').resolve()),
+        'workflow': str((workspace_root / 'docs/open-dataset-workflow.md').resolve()),
+    },
+    'drop_zones': {
+        'fma': str((root / 'data/raw/fma_small_audio').resolve()),
+        'mtg_jamendo': str((root / 'data/raw/mtg_jamendo_audio').resolve()),
+    },
+    'verified_open_smoke_dirs': {
+        'manifests': str((root / 'data/external_ingested/synthetic_as_open_fixed/fma/manifests').resolve()),
+        'reports': str((root / 'reports/open-smoke-fixed/fma').resolve()),
+        'one_shot_reports': str((root / 'data/external_smoke/fma_reports_smoke').resolve()),
+    },
+    'next_commands': {
+        'inspect_fma': '/usr/local/miniconda3/bin/python src/data/external_adapters.py inspect-local fma data/raw/fma_small_audio --eval-ratio 0.2 --query-duration 8.0',
+        'smoke_fma': '/usr/local/miniconda3/bin/python src/data/external_adapters.py smoke-local fma data/raw/fma_small_audio --output-root data/external_smoke --eval-ratio 0.2 --query-duration 8.0 --train-epochs 1 --batch-size 2',
+        'inspect_jamendo': '/usr/local/miniconda3/bin/python src/data/external_adapters.py inspect-local mtg_jamendo data/raw/mtg_jamendo_audio --eval-ratio 0.2 --query-duration 8.0',
+        'smoke_jamendo': '/usr/local/miniconda3/bin/python src/data/external_adapters.py smoke-local mtg_jamendo data/raw/mtg_jamendo_audio --output-root data/external_smoke --eval-ratio 0.2 --query-duration 8.0 --train-epochs 1 --batch-size 2'
+    }
+}
+print(json.dumps(snapshot, ensure_ascii=False, indent=2))

@@ -179,6 +179,29 @@
 - 新 session 现在可以更快进入有效开发状态
 - 启动成本和漏看关键文档/命令的风险进一步下降
 
+### Stage: 状态快照脚本
+
+完成项：
+- 新增 [acr-engine/scripts/status_snapshot.py](../acr-engine/scripts/status_snapshot.py)
+- 统一输出：
+  - latest commit
+  - 核心 docs 路径
+  - 真实数据 drop zones
+  - 已验证 smoke 目录
+  - 下一步推荐命令
+- 将脚本接入 handoff 文档与 first-run checklist
+
+验证结果：
+- `/usr/local/miniconda3/bin/python scripts/status_snapshot.py` 成功
+- 输出已正确指向：
+  - `/workspace/docs/README.md`
+  - `/workspace/docs/session-handoff.md`
+  - `/workspace/docs/open-dataset-workflow.md`
+
+结论：
+- 新 session 现在不只靠静态文档，也可以直接读取当前仓库状态快照
+- 持续开发交接更稳
+
 ### Stage: confused 定向优化 v6（sample-level weighting）
 
 完成项：

@@ -275,6 +275,7 @@
    - [docs/open-dataset-workflow.md](./open-dataset-workflow.md)
    - [docs/session-handoff.md](./session-handoff.md)
    - [acr-engine/FIRST_RUN_CHECKLIST.md](../acr-engine/FIRST_RUN_CHECKLIST.md)
+   - 运行 [acr-engine/scripts/status_snapshot.py](../acr-engine/scripts/status_snapshot.py)
 
 2. 检查真实数据是否已落位：
    - `acr-engine/data/raw/fma_small_audio/`