Add full-stack BTC portfolio web app

Multi-user FastAPI + React app with JWT auth, SQLite storage, and
CoinGecko price integration. Dockerized with docker-compose.

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

btc-portfolio/backend/app/dependencies.py

@@ -0,0 +1,29 @@
+from fastapi import Depends, HTTPException, status
+from fastapi.security import HTTPBearer, HTTPAuthorizationCredentials
+from jose import JWTError
+from sqlalchemy.orm import Session
+
+from .auth import decode_token
+from .database import get_db
+from . import models
+
+bearer_scheme = HTTPBearer()
+
+
+def get_current_user(
+    credentials: HTTPAuthorizationCredentials = Depends(bearer_scheme),
+    db: Session = Depends(get_db),
+) -> models.User:
+    token = credentials.credentials
+    try:
+        payload = decode_token(token)
+        username: str = payload.get("sub")
+        if username is None:
+            raise HTTPException(status_code=status.HTTP_401_UNAUTHORIZED, detail="Invalid token")
+    except JWTError:
+        raise HTTPException(status_code=status.HTTP_401_UNAUTHORIZED, detail="Invalid token")
+
+    user = db.query(models.User).filter(models.User.username == username).first()
+    if user is None:
+        raise HTTPException(status_code=status.HTTP_401_UNAUTHORIZED, detail="User not found")
+    return user