feat: initial project structure

- Add FastAPI app with paper browsing UI and REST API
- Add crawler service and database models
- Add scripts for DB init and manual crawl
- Add docs (api-and-ui, data-model, services)
- Add requirements and project config

app/config.py

@@ -0,0 +1,73 @@
+"""应用配置 — 从 .env / 环境变量加载。"""
+
+from pathlib import Path
+
+from pydantic_settings import BaseSettings
+
+BASE_DIR = Path(__file__).resolve().parent.parent
+
+
+class Settings(BaseSettings):
+    # 应用
+    APP_HOST: str = "127.0.0.1"
+    APP_PORT: int = 8000
+    APP_DEBUG: bool = False
+    BASE_URL: str = "http://127.0.0.1:8000"
+    APP_TIMEZONE: str = "Asia/Shanghai"
+
+    # 安全
+    ADMIN_TOKEN: str = "change-me"
+
+    # HuggingFace / arXiv
+    HF_API_BASE: str = "https://huggingface.co/api"
+    HF_PROXY: str = ""
+    TOP_N: int = 20
+    HTTP_TIMEOUT_SECONDS: int = 30
+    HTTP_MAX_RETRIES: int = 3
+    HTTP_USER_AGENT: str = "hf-daily-papers-local/0.1"
+
+    # AI 总结（Phase 2）
+    PI_BIN: str = ""
+    SUMMARY_SKILL: str = "daily-paper-summary"
+    SUMMARY_CONCURRENCY: int = 3
+    SUMMARY_TIMEOUT_SECONDS: int = 300
+    SUMMARY_MAX_RETRIES: int = 1
+
+    # 调度（Phase 4）
+    SCHEDULER_ENABLED: bool = False
+    SCHEDULE_HOUR: int = 8
+    SCHEDULE_MINUTE: int = 0
+    APP_WORKERS: int = 1
+
+    # 数据库
+    DATABASE_URL: str = "sqlite:///data/db/papers.db"
+
+    # 语义搜索（Phase 5）
+    CHROMA_ENABLED: bool = False
+    CHROMA_DIR: str = "data/chroma"
+    EMBED_API_BASE: str = ""
+    EMBED_API_KEY: str = ""
+    EMBED_MODEL: str = ""
+    EMBED_DIMENSIONS: int = 0
+
+    model_config = {
+        "env_file": str(BASE_DIR / ".env"),
+        "env_file_encoding": "utf-8",
+        "extra": "ignore",
+    }
+
+    @property
+    def db_path(self) -> Path:
+        """从 DATABASE_URL 解析出 SQLite 文件路径。"""
+        # sqlite:///data/db/papers.db → data/db/papers.db
+        url = self.DATABASE_URL
+        if url.startswith("sqlite:///"):
+            return BASE_DIR / url[len("sqlite:///"):]
+        raise ValueError(f"Unsupported DATABASE_URL: {url}")
+
+    @property
+    def http_proxy(self) -> str | None:
+        return self.HF_PROXY or None
+
+
+settings = Settings()