feat: backend gate fallback + metric_diff docs + submit_sft fix

- Auto-inject human-review gate when agent asks question but forgets gate entry
- Add complex_dev/complex_base field docs to program.md metric_diff table
- Fix submit_sft.sh minor issues
- jupyter_runtime improvements

Co-Authored-By: Claude Opus 4.7 <noreply@anthropic.com>

src/jupyter_runtime.py

@@ -297,14 +297,32 @@ class JupyterRuntimeSession:
         if not self.skills_root:
             return
         chat_root = self.chat_workspace_root
-        src = f'{self.skills_root}/model-iteration/scripts/prepare_and_train_sft.py'
-        dst = f'{chat_root}/scripts/prepare_and_train_sft.py'
-        result = self.run_command(
-            (
+        # SKILL/program §5 让 agent 直接 `bash scripts/<x>` 调下面这些脚本，
+        # 不同步过去 → agent 当 "脚本不存在" 处理后会肉手写 yaml，常把
+        # imageCommand 里的 `/scripts/prepare_and_train_sft.py` 写丢前缀，
+        # 导致训练 pod 报 "No such file or directory"。每次 bind 全量覆盖
+        # 一份，跟 prepare_and_train_sft.py 同样 "刷最新版"。
+        script_names = (
+            'prepare_and_train_sft.py',
+            'submit_sft.sh',
+            'sft_train_job.yaml.tpl',
+            'submit_cml_eval.sh',
+            'resolve_run_ids.sh',
+        )
+        src_dir = f'{self.skills_root}/model-iteration/scripts'
+        dst_dir = f'{chat_root}/scripts'
+        copy_cmds = []
+        for name in script_names:
+            src = f'{src_dir}/{name}'
+            dst = f'{dst_dir}/{name}'
+            copy_cmds.append(
                 f'if [ -f {shlex.quote(src)} ]; then '
-                f'cp {shlex.quote(src)} {shlex.quote(dst)}; '
+                f'cp {shlex.quote(src)} {shlex.quote(dst)} && '
+                f'chmod +x {shlex.quote(dst)} 2>/dev/null || true; '
                 f'fi'
-            ),
+            )
+        result = self.run_command(
+            ' && '.join(copy_cmds),
             timeout_seconds=timeout_seconds,
             max_output_chars=2000,
         )