Automate local JoinQuant smoke prep

plugins/joinquant/README.md

@@ -18,6 +18,9 @@ The plugin validates system mechanics, not alpha quality:
 ## Commands
 
 ```bash
+uv run python cli.py joinquant prepare-smoke \
+  --out-dir /tmp/chinese-equity-quant-realdata
+
 uv run python cli.py joinquant export-targets \
   --positions-path portfolio/run1.pq \
   --portfolio-name run1 \
@@ -56,3 +59,8 @@ from `portfolio build`, matching what the internal simulator executes.
 For strict simulator-vs-JoinQuant comparison, pass `--execution-calendar-path`
 so position dates are shifted to the next session open, matching the internal
 simulator's next-open convention.
+
+`prepare-smoke` automates the local side of the first sanity check: tiny real
+data download, one-stock long-only position file, internal simulation, aligned
+target export, wrapper generation, and a manifest with expected JoinQuant CSV
+export paths.