Initial AlphaPulse implementation: news crawler and Binance klines

- Backend (FastAPI, SQLAlchemy 2, Alembic): single-admin cookie auth,
  news/crawler/market APIs with SSE and WebSocket streaming
- Crawler (Scrapy + Scrapy-Redis): wscn_news, wscn_live, cls_depth,
  cls_telegraph spiders, idempotent upserts with revisions, raw response
  archiving, per-source subprocess supervision, restart and backoff
- Market worker: full-history Binance spot/USD-M kline backfill,
  realtime WS stream, hourly and on-reconnect catch-up
- Frontend (Vue 3, Element Plus, UnoCSS, KLineChart): news feed,
  crawler console with live logs, Binance-style chart page
- Deploy: docker compose, nginx site, migrate and daily backup scripts

backend/src/alphapulse/core/config.py

@@ -0,0 +1,20 @@
+from functools import lru_cache
+
+from pydantic_settings import BaseSettings, SettingsConfigDict
+
+
+class Settings(BaseSettings):
+    # 容器内由 compose 的 env_file 注入；只有一套配置，见仓库根目录 .env
+    model_config = SettingsConfigDict(extra="ignore")
+
+    database_url: str
+    redis_url: str
+    jwt_secret: str
+    admin_username: str
+    admin_password_hash: str = ""
+    jwt_expire_days: int = 7
+
+
+@lru_cache
+def get_settings() -> Settings:
+    return Settings()