chore: manage env with uv (pyproject + lockfile)

Migrate dependency management from requirements.txt to uv. Runtime deps
move to pyproject.toml with pytest in the dev group; uv.lock pins the
resolved set. Docs updated to use `uv sync` / `uv run`.

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

README.md

@@ -39,36 +39,38 @@ Data comes from **baostock (primary)** with **akshare (fallback)**.
 
 ## Install
 
+The env is managed with [uv](https://docs.astral.sh/uv/). `uv sync` builds `.venv` from `pyproject.toml` + `uv.lock`; prefix commands with `uv run` (no manual activation needed).
+
 ```bash
-pip install -r requirements.txt
+uv sync
 ```
 
 ## Quick start
 
 ```bash
 # 1. Download daily bars for a few symbols (writes a month-partitioned dataset).
-python3 cli.py data download \
+uv run python cli.py data download \
     --universe sh600000,sz000001,sh600519 \
     --start-date 2024-01-01 --end-date 2024-03-31 \
     --output-dir data/daily_bars
 
 # 2. Compute an alpha (position weights) from that data.
 #    --data-path is the dataset DIRECTORY ({output-dir}/{universe}).
-python3 cli.py alpha reversal \
+uv run python cli.py alpha reversal \
     --data-path "data/daily_bars/sh600000,sz000001,sh600519"
 
 # 3. Evaluate it (return / Sharpe / turnover / drawdown).
-python3 cli.py alpha eval \
+uv run python cli.py alpha eval \
     --alpha-path alphas/reversal_5d.pq \
     --data-path  "data/daily_bars/sh600000,sz000001,sh600519"
 
 # Tests
-python3 -m pytest tests/ -v        # tests/test_alpha.py is network-free; test_downloader.py hits the network
+uv run python -m pytest tests/ -v        # tests/test_alpha.py is network-free; test_downloader.py hits the network
 ```
 
 ## CLI reference
 
-All commands are subcommands of `python3 cli.py`. Add `--help` to any of them.
+All commands are subcommands of `uv run python cli.py`. Add `--help` to any of them.
 
 ### `data download` — fetch daily bars → partitioned parquet dataset
 
@@ -93,8 +95,8 @@ set. Symbols use the internal `sh600000` / `sz000001` form (exchange prefix + co
 ### `alpha list` — show registered alpha types
 
 ```bash
-python3 cli.py alpha list
-python3 cli.py alpha list --alpha-module path/to/my_alpha.py   # include an external alpha
+uv run python cli.py alpha list
+uv run python cli.py alpha list --alpha-module path/to/my_alpha.py   # include an external alpha
 ```
 
 ### `alpha compute` — alpha class → weights parquet
@@ -114,7 +116,7 @@ Only the params an alpha's `__init__` accepts are forwarded, so passing extras
 (e.g. `--vol-window` to a reversal alpha) is harmless.
 
 ```bash
-python3 cli.py alpha compute \
+uv run python cli.py alpha compute \
     --data-path <data>.pq \
     --alpha-type reversal_vol --alpha-name rv_5_20 \
     --lookback 5 --vol-window 20
@@ -123,14 +125,14 @@ python3 cli.py alpha compute \
 Shortcuts for the two most common built-ins:
 
 ```bash
-python3 cli.py alpha reversal     --data-path <data>.pq --lookback 5
-python3 cli.py alpha reversal-vol --data-path <data>.pq --lookback 5 --vol-window 20
+uv run python cli.py alpha reversal     --data-path <data>.pq --lookback 5
+uv run python cli.py alpha reversal-vol --data-path <data>.pq --lookback 5 --vol-window 20
 ```
 
 ### `alpha eval` — score an alpha as a portfolio
 
 ```bash
-python3 cli.py alpha eval --alpha-path alphas/<name>.pq --data-path <data>.pq
+uv run python cli.py alpha eval --alpha-path alphas/<name>.pq --data-path <data>.pq
 ```
 
 Interprets the weights as a portfolio and reports cumulative return, annual
@@ -148,7 +150,7 @@ position weights, not return predictors.
 | `--output-dir` | `combos` | Output directory |
 
 ```bash
-python3 cli.py combo combine \
+uv run python cli.py combo combine \
     --alpha-paths alphas/reversal_5d.pq,alphas/reversal_vol_5d_20d.pq \
     --combo-name eq --method equal_weight
 ```
@@ -166,9 +168,9 @@ directory) to stdout, without writing a throwaway script.
 | `--info` | off | Show shape + dtypes instead of the rows |
 
 ```bash
-python3 cli.py pqcat alphas/reversal_5d.pq                       # dump all rows
-python3 cli.py pqcat data/daily_bars/csi500 --info              # shape + dtypes
-python3 cli.py pqcat data/daily_bars/csi500 -n 10 -c symbol_id,date,close,vwap
+uv run python cli.py pqcat alphas/reversal_5d.pq                       # dump all rows
+uv run python cli.py pqcat data/daily_bars/csi500 --info              # shape + dtypes
+uv run python cli.py pqcat data/daily_bars/csi500 -n 10 -c symbol_id,date,close,vwap
 ```
 
 **Standalone command.** `tools/pqcat.py` has no repo dependencies, so it can be
@@ -195,7 +197,7 @@ volume over a time range.
 | `-c, --columns` | `close,volume` | Comma-separated bar columns to show |
 
 ```bash
-python3 cli.py alphaview \
+uv run python cli.py alphaview \
     --data-path data/daily_bars/csi500 \
     --alpha-path alphas/reversal_5d.pq,alphas/momentum_5d.pq \
     --symbol sh600000 --start-date 2024-01-01 --end-date 2024-03-31 \
@@ -260,7 +262,7 @@ with `--alpha-module` (a `.py` path or an importable dotted module). See the
 worked example in `examples/alphas/mean_reversion.py`:
 
 ```bash
-python3 cli.py alpha compute \
+uv run python cli.py alpha compute \
     --alpha-module examples/alphas/mean_reversion.py \
     --alpha-type mean_reversion --alpha-name mr20 \
     --param window=20 \