feat(deps): add uv-backed package installer (#5987)

* feat(deps): add uv-backed package installer

* feat(deps): support package cache root

scripts/dev/simulate_package_installer.py

@@ -0,0 +1,74 @@
+#!/usr/bin/env python3
+
+from __future__ import annotations
+
+import sys
+from pathlib import Path
+
+ROOT = Path(__file__).resolve().parents[2]
+sys.path.insert(0, str(ROOT))
+
+from app.helper.package_installer import PackageInstallRequest, build_package_install_strategies
+
+
+def sample(name: str, request: PackageInstallRequest) -> None:
+    print(f"## {name}")
+    strategies = build_package_install_strategies(request)
+    assert strategies, f"{name}: no strategies generated"
+    for strategy in strategies:
+        rendered = " ".join(strategy.safe_log_command)
+        print(strategy.strategy_name)
+        print(rendered)
+        assert all("--proxy" not in arg for arg in strategy.command)
+        assert "user:pass" not in rendered
+        assert strategy.env["PIP_CACHE_DIR"].endswith("/.cache/pip")
+        assert strategy.env["UV_CACHE_DIR"].endswith("/.cache/uv")
+        if strategy.strategy_name.endswith("代理") or strategy.strategy_name.endswith("镜像+代理"):
+            assert strategy.env["HTTPS_PROXY"] == "http://proxy.example:7890"
+
+
+def main() -> None:
+    root = ROOT
+    config_dir = root / "config"
+    python_bin = root.parent / ".venv-test" / "bin" / "python"
+    requirements = root / "requirements.txt"
+
+    samples = {
+        "plain": PackageInstallRequest(
+            requirements_file=requirements,
+            python_bin=python_bin,
+            config_dir=config_dir,
+        ),
+        "mirror": PackageInstallRequest(
+            requirements_file=requirements,
+            python_bin=python_bin,
+            config_dir=config_dir,
+            pip_index_url="https://user:pass@mirror.example/simple",
+        ),
+        "proxy": PackageInstallRequest(
+            requirements_file=requirements,
+            python_bin=python_bin,
+            config_dir=config_dir,
+            proxy_url="http://proxy.example:7890",
+        ),
+        "mirror_proxy_wheels": PackageInstallRequest(
+            requirements_file=requirements,
+            python_bin=python_bin,
+            config_dir=config_dir,
+            find_links_dirs=[
+                root / "plugins.v2" / "demo" / "wheels",
+                root / "plugins.v2" / "other" / "wheels",
+            ],
+            pip_index_url="https://user:pass@mirror.example/simple",
+            proxy_url="http://proxy.example:7890",
+        ),
+    }
+
+    for name, request in samples.items():
+        sample(name, request)
+
+    print("Package installer simulation passed")
+
+
+if __name__ == "__main__":
+    main()