Add JoinQuant browser backtest automation

docs/joinquant_comparison_plugin.md

@@ -238,6 +238,65 @@ The command downloads a tiny public daily-bar sample, builds a fixed-share
 JoinQuant target files, writes a configured wrapper strategy, and creates
 `joinquant_smoke_manifest.json` with all output paths.
 
+## Browser Backtest Automation
+
+JoinQuant's public `jqdatasdk` is a data SDK. It supports authenticated data
+calls such as `auth(username, password)` and `get_price(...)`, but cloud
+strategy upload, backtest execution, and result export are web-application
+workflows. The plugin therefore automates those remote steps through Playwright
+with a saved browser session.
+
+Install the optional browser runner in the uv environment:
+
+```bash
+uv sync --extra joinquant-browser
+uv run playwright install chromium
+```
+
+Save a reusable login state. This opens a browser; log in normally, including
+any CAPTCHA or 2FA, then press Enter in the terminal to save state:
+
+```bash
+uv run python cli.py joinquant browser-login \
+  --storage-state ~/.config/chinese-equity-quant/joinquant_storage_state.json
+```
+
+Create a selector/action config:
+
+```bash
+uv run python cli.py joinquant write-browser-config \
+  --out-path /tmp/chinese-equity-quant-realdata/joinquant_browser_config.json \
+  --strategy-url "https://www.joinquant.com/<your strategy page>"
+```
+
+If selectors need tuning, capture the logged-in page:
+
+```bash
+uv run python cli.py joinquant browser-snapshot \
+  --url "https://www.joinquant.com/<your strategy page>" \
+  --out-dir /tmp/chinese-equity-quant-realdata/browser_snapshot
+```
+
+Then run the remote backtest automation:
+
+```bash
+uv run python cli.py joinquant run-browser-backtest \
+  --manifest-path /tmp/chinese-equity-quant-realdata/joinquant_smoke_manifest.json \
+  --config-path /tmp/chinese-equity-quant-realdata/joinquant_browser_config.json \
+  --storage-state ~/.config/chinese-equity-quant/joinquant_storage_state.json \
+  --headed
+```
+
+The config is declarative: actions can navigate, paste the generated wrapper,
+upload all target CSV files, fill dates, click run, wait for completion,
+download result CSVs, and take screenshots. When the configured downloads
+produce fills, positions, and PnL CSVs, the runner automatically calls
+`joinquant ingest` and `joinquant reconcile`.
+
+Do not store raw JoinQuant passwords in this repository. The browser state file
+is created with `0600` permissions and should live under `~/.config`, outside
+the repo.
+
 ## Recommended First Sanity Checks
 
 1. One liquid stock with a fixed target share count.