Vendor backend and frontend into the monorepo

The submodule collapse was only half applied: .gitmodules was deleted but
backend/ and frontend/ were still recorded as gitlinks, so none of their
files were tracked. Replace the gitlinks with the real trees.

Also untrack .env (it carried placeholder secrets) in favour of a tracked
.env.example, drop the committed __pycache__, and narrow the blanket *.png
ignore that would have swallowed design assets.

Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>

backend/tests/utils/item.py

@@ -0,0 +1,16 @@
+from sqlmodel import Session
+
+from app import crud
+from app.models import Item, ItemCreate
+from tests.utils.user import create_random_user
+from tests.utils.utils import random_lower_string
+
+
+def create_random_item(db: Session) -> Item:
+    user = create_random_user(db)
+    owner_id = user.id
+    assert owner_id is not None
+    title = random_lower_string()
+    description = random_lower_string()
+    item_in = ItemCreate(title=title, description=description)
+    return crud.create_item(session=db, item_in=item_in, owner_id=owner_id)

backend/tests/utils/user.py

@@ -0,0 +1,49 @@
+from fastapi.testclient import TestClient
+from sqlmodel import Session
+
+from app import crud
+from app.core.config import settings
+from app.models import User, UserCreate, UserUpdate
+from tests.utils.utils import random_email, random_lower_string
+
+
+def user_authentication_headers(
+    *, client: TestClient, email: str, password: str
+) -> dict[str, str]:
+    data = {"username": email, "password": password}
+
+    r = client.post(f"{settings.API_V1_STR}/login/access-token", data=data)
+    response = r.json()
+    auth_token = response["access_token"]
+    headers = {"Authorization": f"Bearer {auth_token}"}
+    return headers
+
+
+def create_random_user(db: Session) -> User:
+    email = random_email()
+    password = random_lower_string()
+    user_in = UserCreate(email=email, password=password)
+    user = crud.create_user(session=db, user_create=user_in)
+    return user
+
+
+def authentication_token_from_email(
+    *, client: TestClient, email: str, db: Session
+) -> dict[str, str]:
+    """
+    Return a valid token for the user with given email.
+
+    If the user doesn't exist it is created first.
+    """
+    password = random_lower_string()
+    user = crud.get_user_by_email(session=db, email=email)
+    if not user:
+        user_in_create = UserCreate(email=email, password=password)
+        user = crud.create_user(session=db, user_create=user_in_create)
+    else:
+        user_in_update = UserUpdate(password=password)
+        if not user.id:
+            raise Exception("User id not set")
+        user = crud.update_user(session=db, db_user=user, user_in=user_in_update)
+
+    return user_authentication_headers(client=client, email=email, password=password)

backend/tests/utils/utils.py

@@ -0,0 +1,26 @@
+import random
+import string
+
+from fastapi.testclient import TestClient
+
+from app.core.config import settings
+
+
+def random_lower_string() -> str:
+    return "".join(random.choices(string.ascii_lowercase, k=32))
+
+
+def random_email() -> str:
+    return f"{random_lower_string()}@{random_lower_string()}.com"
+
+
+def get_superuser_token_headers(client: TestClient) -> dict[str, str]:
+    login_data = {
+        "username": settings.FIRST_SUPERUSER,
+        "password": settings.FIRST_SUPERUSER_PASSWORD,
+    }
+    r = client.post(f"{settings.API_V1_STR}/login/access-token", data=login_data)
+    tokens = r.json()
+    a_token = tokens["access_token"]
+    headers = {"Authorization": f"Bearer {a_token}"}
+    return headers