feat(datagen): add reserve grid positions and batch codes to lab config

- introduce reserve grid positions for QA witness pattern
- add batch codes to run entries in lab configuration
- update schedule with run start time and track interval
- enhance validation checks for run-batch mapping

docs/rules/meta-cursor-rules.md

@@ -46,6 +46,10 @@ one-click SCM generator falls back to Cursor defaults and emits unprefixed junk
    project`, `clarify rules`).
 6. **Allowed special forms** - `Merge ...` commits are allowed as-is;
    `release(scope): vX.Y.Z` is allowed for releases.
+7. **Staged-diff grounding** - base the message ONLY on `git diff --cached`;
+   mention only staged paths; if the index is empty, output `No staged
+   changes`; never infer from unstaged diffs, untracked files, prior
+   commits, or chat context.
 
 ## 3. Keeping the mirror in sync