feat: migrate backend to uv package manager

Replace pip + requirements.txt with uv for dependency management.

- Multi-stage Dockerfile using ghcr.io/astral-sh/uv builder image
- CI updated to use astral-sh/setup-uv@v4
- Ruff config moved to [tool.ruff.lint] (fixes deprecation)
- Transitive deps removed, missing direct deps added (requests, PySocks, urllib3)
- Database layer migrated to async (AsyncSession + aiosqlite)
- Tests updated to match async database interface

Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>

backend/pyproject.toml

@@ -4,109 +4,61 @@ version = "3.1.0"
 description = "AutoBangumi - Automated anime download manager"
 requires-python = ">=3.10"
 dependencies = [
-    "anyio>=4.0.0",
-    "beautifulsoup4>=4.12.0",
-    "certifi>=2023.5.7",
-    "charset-normalizer>=3.1.0",
-    "click>=8.1.3",
     "fastapi>=0.109.0",
-    "h11>=0.14.0",
-    "idna>=3.4",
-    "pydantic>=2.0.0",
-    "sniffio>=1.3.0",
-    "soupsieve>=2.4.1",
-    "typing_extensions>=4.0.0",
-    "urllib3>=2.0.3",
     "uvicorn>=0.27.0",
-    "Jinja2>=3.1.2",
-    "python-dotenv>=1.0.0",
+    "httpx>=0.25.0",
+    "httpx-socks>=0.9.0",
+    "beautifulsoup4>=4.12.0",
+    "sqlmodel>=0.0.14",
+    "sqlalchemy[asyncio]>=2.0.0",
+    "aiosqlite>=0.19.0",
+    "pydantic>=2.0.0",
     "python-jose>=3.3.0",
     "passlib>=1.7.4",
     "bcrypt>=4.0.1,<4.1",
     "python-multipart>=0.0.6",
-    "sqlmodel>=0.0.14",
-    "sse-starlette>=1.6.5",
-    "semver>=3.0.1",
+    "python-dotenv>=1.0.0",
+    "Jinja2>=3.1.2",
     "openai>=1.54.3",
-    "httpx>=0.25.0",
-    "httpx-socks>=0.9.0",
-    "aiosqlite>=0.19.0",
-    "sqlalchemy[asyncio]>=2.0.0",
+    "semver>=3.0.1",
+    "sse-starlette>=1.6.5",
     "webauthn>=2.0.0",
+    "urllib3>=2.0.3",
+    "requests>=2.31.0",
+    "PySocks>=1.7.1",
 ]
 
-[project.optional-dependencies]
+[dependency-groups]
 dev = [
     "pytest>=8.0.0",
     "pytest-asyncio>=0.23.0",
     "ruff>=0.1.0",
     "black>=24.0.0",
+    "pre-commit>=3.0.0",
 ]
 
 [tool.pytest.ini_options]
 testpaths = ["src/test"]
+pythonpath = ["src"]
 asyncio_mode = "auto"
 
 [tool.ruff]
-select = [
-    # pycodestyle(E): https://beta.ruff.rs/docs/rules/#pycodestyle-e-w
-    "E",
-    # Pyflakes(F): https://beta.ruff.rs/docs/rules/#pyflakes-f
-    "F",
-    # isort(I): https://beta.ruff.rs/docs/rules/#isort-i
-    "I"
-]
-ignore = [
-    # E501: https://beta.ruff.rs/docs/rules/line-too-long/
-    'E501',
-    # F401: https://beta.ruff.rs/docs/rules/unused-import/
-    # avoid unused imports lint in `__init__.py`
-    'F401',
-]
+line-length = 88
+target-version = "py310"
+exclude = [".venv", "venv", "build", "dist"]
 
-# Allow autofix for all enabled rules (when `--fix`) is provided.
-fixable = ["A", "B", "C", "D", "E", "F", "G", "I", "N", "Q", "S", "T", "W", "ANN", "ARG", "BLE", "COM", "DJ", "DTZ", "EM", "ERA", "EXE", "FBT", "ICN", "INP", "ISC", "NPY", "PD", "PGH", "PIE", "PL", "PT", "PTH", "PYI", "RET", "RSE", "RUF", "SIM", "SLF", "TCH", "TID", "TRY", "UP", "YTT"]
+[tool.ruff.lint]
+select = ["E", "F", "I"]
+ignore = ["E501", "F401"]
+fixable = ["ALL"]
 unfixable = []
 
-# Exclude a variety of commonly ignored directories.
-exclude = [
-    ".bzr",
-    ".direnv",
-    ".eggs",
-    ".git",
-    ".git-rewrite",
-    ".hg",
-    ".mypy_cache",
-    ".nox",
-    ".pants.d",
-    ".pytype",
-    ".ruff_cache",
-    ".svn",
-    ".tox",
-    ".venv",
-    "__pypackages__",
-    "_build",
-    "buck-out",
-    "build",
-    "dist",
-    "node_modules",
-    "venv",
-]
-per-file-ignores = {}
-
-# Same as Black.
-line-length = 88
-
-# Allow unused variables when underscore-prefixed.
-dummy-variable-rgx = "^(_+|(_+[a-zA-Z0-9_]*[a-zA-Z0-9]+?))$"
-
-# Assume Python 3.10.
-target-version = "py310"
-
-[tool.ruff.mccabe]
-# Unlike Flake8, default to a complexity level of 10.
+[tool.ruff.lint.mccabe]
 max-complexity = 10
 
+[tool.uv]
+package = false
+
 [tool.black]
 line-length = 88
 target-version = ['py310', 'py311']