feat(auth): Add optional authentication system (#22)

Backend:
- Add User model with username, hashed password, role, is_active
- Add passlib[bcrypt] and python-jose[cryptography] dependencies
- Create auth.py with JWT utilities, password hashing, role checking
- Add /auth endpoints: status, setup, login, me, users CRUD
- Add role-based permission system (viewer/operator/editor/admin)
- Environment: SPOOLMAN_AUTH_ENABLED, SPOOLMAN_AUTH_SECRET_KEY
- Migration for user table

Frontend:
- Add AuthProvider context with login/logout/setup
- Add LoginPage component with setup mode for first user
- Add ProtectedRoute wrapper for auth-required pages
- Add axios interceptor to attach JWT token to requests
- Add User Management tab in Settings (admin only)
- Add translation keys for auth UI

When SPOOLMAN_AUTH_ENABLED=true:
- Users must login to access the app
- First visit shows setup page to create admin account
- Role-based access control for future endpoint protection

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

spoolman/api/v1/auth.py

@@ -0,0 +1,289 @@
+"""Authentication API endpoints."""
+
+import logging
+from datetime import datetime
+from typing import Annotated, Optional
+
+from fastapi import APIRouter, Depends, HTTPException, status
+from fastapi.security import OAuth2PasswordRequestForm
+from pydantic import BaseModel, Field
+from sqlalchemy import func, select
+from sqlalchemy.ext.asyncio import AsyncSession
+
+from spoolman import auth
+from spoolman.auth import (
+    RequireAdmin,
+    Role,
+    Token,
+    UserResponse,
+    authenticate_user,
+    create_access_token,
+    get_current_user,
+    get_password_hash,
+    get_user_by_username,
+    is_auth_enabled,
+)
+from spoolman.database import models
+from spoolman.database.database import get_db_session
+
+logger = logging.getLogger(__name__)
+
+router = APIRouter(
+    prefix="/auth",
+    tags=["auth"],
+)
+
+
+class AuthStatusResponse(BaseModel):
+    """Authentication status response."""
+
+    enabled: bool
+    has_users: bool
+
+
+class UserCreateRequest(BaseModel):
+    """Request to create a new user."""
+
+    username: str = Field(..., min_length=3, max_length=64)
+    password: str = Field(..., min_length=6)
+    role: Role = Role.VIEWER
+
+
+class UserUpdateRequest(BaseModel):
+    """Request to update a user."""
+
+    password: Optional[str] = Field(None, min_length=6)
+    role: Optional[Role] = None
+    is_active: Optional[bool] = None
+
+
+class SetupRequest(BaseModel):
+    """Initial setup request to create admin user."""
+
+    username: str = Field(..., min_length=3, max_length=64)
+    password: str = Field(..., min_length=6)
+
+
+@router.get(
+    "/status",
+    name="Get auth status",
+    description="Check if authentication is enabled and if any users exist.",
+    response_model=AuthStatusResponse,
+)
+async def get_auth_status(
+    db: Annotated[AsyncSession, Depends(get_db_session)],
+) -> AuthStatusResponse:
+    """Get authentication status."""
+    result = await db.execute(select(func.count()).select_from(models.User))
+    user_count = result.scalar() or 0
+    return AuthStatusResponse(
+        enabled=is_auth_enabled(),
+        has_users=user_count > 0,
+    )
+
+
+@router.post(
+    "/setup",
+    name="Initial setup",
+    description="Create the first admin user. Only works if no users exist.",
+    response_model=UserResponse,
+)
+async def setup(
+    body: SetupRequest,
+    db: Annotated[AsyncSession, Depends(get_db_session)],
+) -> UserResponse:
+    """Create the first admin user during initial setup."""
+    # Check if any users exist
+    result = await db.execute(select(func.count()).select_from(models.User))
+    user_count = result.scalar() or 0
+
+    if user_count > 0:
+        raise HTTPException(
+            status_code=status.HTTP_400_BAD_REQUEST,
+            detail="Setup already completed. Users already exist.",
+        )
+
+    # Create admin user
+    user = models.User(
+        username=body.username,
+        hashed_password=get_password_hash(body.password),
+        role=Role.ADMIN.value,
+        is_active=True,
+        created_at=datetime.utcnow(),
+    )
+    db.add(user)
+    await db.commit()
+    await db.refresh(user)
+
+    logger.info("Initial admin user created: %s", body.username)
+    return UserResponse.from_db(user)
+
+
+@router.post(
+    "/login",
+    name="Login",
+    description="Authenticate and get an access token.",
+    response_model=Token,
+)
+async def login(
+    form_data: Annotated[OAuth2PasswordRequestForm, Depends()],
+    db: Annotated[AsyncSession, Depends(get_db_session)],
+) -> Token:
+    """Authenticate user and return JWT token."""
+    if not is_auth_enabled():
+        raise HTTPException(
+            status_code=status.HTTP_400_BAD_REQUEST,
+            detail="Authentication is not enabled",
+        )
+
+    user = await authenticate_user(db, form_data.username, form_data.password)
+    if not user:
+        raise HTTPException(
+            status_code=status.HTTP_401_UNAUTHORIZED,
+            detail="Incorrect username or password",
+            headers={"WWW-Authenticate": "Bearer"},
+        )
+
+    access_token = create_access_token(
+        data={"sub": user.username, "role": user.role}
+    )
+    return Token(access_token=access_token)
+
+
+@router.get(
+    "/me",
+    name="Get current user",
+    description="Get the currently authenticated user's info.",
+    response_model=UserResponse,
+)
+async def get_me(
+    current_user: Annotated[Optional[models.User], Depends(get_current_user)],
+) -> UserResponse:
+    """Get current user info."""
+    if current_user is None:
+        raise HTTPException(
+            status_code=status.HTTP_401_UNAUTHORIZED,
+            detail="Not authenticated",
+        )
+    return UserResponse.from_db(current_user)
+
+
+# User management endpoints (admin only)
+
+
+@router.get(
+    "/users",
+    name="List users",
+    description="Get all users (admin only).",
+    response_model=list[UserResponse],
+    dependencies=[RequireAdmin],
+)
+async def list_users(
+    db: Annotated[AsyncSession, Depends(get_db_session)],
+) -> list[UserResponse]:
+    """List all users."""
+    result = await db.execute(select(models.User).order_by(models.User.username))
+    users = result.scalars().all()
+    return [UserResponse.from_db(u) for u in users]
+
+
+@router.post(
+    "/users",
+    name="Create user",
+    description="Create a new user (admin only).",
+    response_model=UserResponse,
+    dependencies=[RequireAdmin],
+)
+async def create_user(
+    body: UserCreateRequest,
+    db: Annotated[AsyncSession, Depends(get_db_session)],
+) -> UserResponse:
+    """Create a new user."""
+    # Check if username exists
+    existing = await get_user_by_username(db, body.username)
+    if existing:
+        raise HTTPException(
+            status_code=status.HTTP_400_BAD_REQUEST,
+            detail="Username already exists",
+        )
+
+    user = models.User(
+        username=body.username,
+        hashed_password=get_password_hash(body.password),
+        role=body.role.value,
+        is_active=True,
+        created_at=datetime.utcnow(),
+    )
+    db.add(user)
+    await db.commit()
+    await db.refresh(user)
+
+    logger.info("User created: %s (role: %s)", body.username, body.role.value)
+    return UserResponse.from_db(user)
+
+
+@router.patch(
+    "/users/{user_id}",
+    name="Update user",
+    description="Update a user (admin only).",
+    response_model=UserResponse,
+    dependencies=[RequireAdmin],
+)
+async def update_user(
+    user_id: int,
+    body: UserUpdateRequest,
+    db: Annotated[AsyncSession, Depends(get_db_session)],
+) -> UserResponse:
+    """Update a user."""
+    user = await db.get(models.User, user_id)
+    if not user:
+        raise HTTPException(
+            status_code=status.HTTP_404_NOT_FOUND,
+            detail="User not found",
+        )
+
+    if body.password is not None:
+        user.hashed_password = get_password_hash(body.password)
+    if body.role is not None:
+        user.role = body.role.value
+    if body.is_active is not None:
+        user.is_active = body.is_active
+
+    await db.commit()
+    await db.refresh(user)
+
+    logger.info("User updated: %s", user.username)
+    return UserResponse.from_db(user)
+
+
+@router.delete(
+    "/users/{user_id}",
+    name="Delete user",
+    description="Delete a user (admin only).",
+    dependencies=[RequireAdmin],
+)
+async def delete_user(
+    user_id: int,
+    current_user: Annotated[Optional[models.User], Depends(get_current_user)],
+    db: Annotated[AsyncSession, Depends(get_db_session)],
+) -> dict:
+    """Delete a user."""
+    user = await db.get(models.User, user_id)
+    if not user:
+        raise HTTPException(
+            status_code=status.HTTP_404_NOT_FOUND,
+            detail="User not found",
+        )
+
+    # Prevent self-deletion
+    if current_user and user.id == current_user.id:
+        raise HTTPException(
+            status_code=status.HTTP_400_BAD_REQUEST,
+            detail="Cannot delete your own account",
+        )
+
+    await db.delete(user)
+    await db.commit()
+
+    logger.info("User deleted: %s", user.username)
+    return {"message": "User deleted"}