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/routes/users.py

@@ -0,0 +1,42 @@
+from fastapi import APIRouter, Depends, HTTPException, status
+from sqlalchemy.orm import Session
+from pydantic import BaseModel
+
+from ..database import get_db
+from .. import models
+from ..auth import hash_password, verify_password, create_access_token
+
+router = APIRouter()
+
+
+class UserCreate(BaseModel):
+    username: str
+    password: str
+
+
+class Token(BaseModel):
+    access_token: str
+    token_type: str
+
+
+@router.post("/register", status_code=status.HTTP_201_CREATED)
+def register(user_in: UserCreate, db: Session = Depends(get_db)):
+    existing = db.query(models.User).filter(models.User.username == user_in.username).first()
+    if existing:
+        raise HTTPException(status_code=400, detail="Username already taken")
+    user = models.User(
+        username=user_in.username,
+        password=hash_password(user_in.password),
+    )
+    db.add(user)
+    db.commit()
+    return {"message": "User created"}
+
+
+@router.post("/login", response_model=Token)
+def login(user_in: UserCreate, db: Session = Depends(get_db)):
+    user = db.query(models.User).filter(models.User.username == user_in.username).first()
+    if not user or not verify_password(user_in.password, user.password):
+        raise HTTPException(status_code=401, detail="Invalid credentials")
+    token = create_access_token({"sub": user.username})
+    return {"access_token": token, "token_type": "bearer"}