added multi user support, move api key to database

backend/app/routers/users.py

@@ -0,0 +1,114 @@
+"""Admin-portal user management. Every endpoint requires an admin — regular
+users cannot create, delete, or reset the password of any account (they can
+only change their own password via ``/auth/change-password``).
+"""
+
+from fastapi import APIRouter, Depends, Request
+from sqlalchemy import func, select
+from sqlalchemy.orm import Session as DbSession
+
+from .. import auth
+from ..auth import require_admin
+from ..database import get_db
+from ..errors import APIError
+from ..models import Admin, Session
+from ..schemas import AdminCreate, AdminOut, ResetPasswordRequest
+
+router = APIRouter(prefix="/users", tags=["users"])
+
+
+@router.get("", response_model=list[AdminOut])
+def list_users(_: Admin = Depends(require_admin), db: DbSession = Depends(get_db)):
+    return db.execute(select(Admin).order_by(Admin.id)).scalars().all()
+
+
+@router.post("", response_model=AdminOut, status_code=201)
+def create_user(
+    payload: AdminCreate,
+    request: Request,
+    admin: Admin = Depends(require_admin),
+    db: DbSession = Depends(get_db),
+):
+    exists = db.execute(
+        select(Admin.id).where(Admin.username == payload.username)
+    ).scalar_one_or_none()
+    if exists is not None:
+        raise APIError(status_code=409, detail=f"User '{payload.username}' already exists")
+
+    user = Admin(
+        username=payload.username,
+        password_hash=auth.hash_password(payload.password),
+        is_admin=payload.is_admin,
+        must_change_password=payload.force_password_change,
+    )
+    db.add(user)
+    db.commit()
+    db.refresh(user)
+    auth.record_log(
+        db,
+        username=admin.username,
+        action="create_user",
+        detail=f"Created user '{user.username}'" + (" (admin)" if user.is_admin else ""),
+        request=request,
+    )
+    return user
+
+
+@router.delete("/{user_id}", status_code=204)
+def delete_user(
+    user_id: int,
+    request: Request,
+    admin: Admin = Depends(require_admin),
+    db: DbSession = Depends(get_db),
+):
+    if user_id == admin.id:
+        raise APIError(status_code=400, detail="You cannot delete your own account")
+    user = db.get(Admin, user_id)
+    if user is None:
+        raise APIError(status_code=404, detail=f"User '{user_id}' not found")
+    if user.is_admin:
+        admin_count = db.execute(
+            select(func.count()).select_from(Admin).where(Admin.is_admin.is_(True))
+        ).scalar_one()
+        if admin_count <= 1:
+            raise APIError(status_code=400, detail="Cannot delete the last administrator")
+
+    # Drop the user's sessions too so any live token stops working immediately.
+    for s in db.execute(select(Session).where(Session.admin_id == user.id)).scalars().all():
+        db.delete(s)
+    db.delete(user)
+    db.commit()
+    auth.record_log(
+        db,
+        username=admin.username,
+        action="delete_user",
+        detail=f"Deleted user '{user.username}'",
+        request=request,
+    )
+
+
+@router.post("/{user_id}/reset-password", status_code=204)
+def reset_password(
+    user_id: int,
+    payload: ResetPasswordRequest,
+    request: Request,
+    admin: Admin = Depends(require_admin),
+    db: DbSession = Depends(get_db),
+):
+    """Admin resets another user's password; they must change it on next login."""
+    user = db.get(Admin, user_id)
+    if user is None:
+        raise APIError(status_code=404, detail=f"User '{user_id}' not found")
+    user.password_hash = auth.hash_password(payload.new_password)
+    user.must_change_password = payload.force_password_change
+    # Invalidate existing sessions so the old password/session can't be reused.
+    for s in db.execute(select(Session).where(Session.admin_id == user.id)).scalars().all():
+        db.delete(s)
+    db.commit()
+    auth.record_log(
+        db,
+        username=admin.username,
+        action="reset_password",
+        detail=f"Reset password for '{user.username}'",
+        request=request,
+    )