Give the tests their own database and drop the template specs

pytest was deleting every user on teardown against the development
database. The engine is built at import time, so tests/__init__.py pins
POSTGRES_DB before app.core.config loads; the fixture creates the schema
and drops the database again, guarded against a name that is not _test.

Playwright now defaults at the integrated stack, which is the origin the
API allows, so a bare `bunx playwright test` works without a dev server.
The four template specs that asserted copy we no longer ship are gone,
along with the helpers they were the last callers of. The admin edit
assertion was page-wide and only ever passed on a fresh database.

Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01KkmeRiyeYmVZqJVwuyHq9o

backend/tests/conftest.py

@@ -2,12 +2,13 @@ from collections.abc import Generator
 
 import pytest
 from fastapi.testclient import TestClient
-from sqlmodel import Session, delete
+from sqlalchemy import create_engine, text
+from sqlalchemy.engine import make_url
+from sqlmodel import Session, SQLModel
 
 from app.core.config import settings
 from app.core.db import engine, init_db
 from app.main import app
-from app.models import User
 from tests.utils.user import authentication_token_from_email
 from tests.utils.utils import get_superuser_token_headers
 
@@ -23,12 +24,29 @@ def flow_data(tmp_path_factory: pytest.TempPathFactory) -> Generator[None, None,
 
 @pytest.fixture(scope="session", autouse=True)
 def db() -> Generator[Session, None, None]:
+    """Create the throwaway database `tests/__init__.py` points at, drop it after."""
+    url = make_url(str(settings.SQLALCHEMY_DATABASE_URI))
+    # The teardown drops this database, so refuse to run against anything but
+    # the dedicated test one.
+    assert url.database and url.database.endswith("_test"), url.database
+
+    maintenance = create_engine(
+        url.set(database="postgres"), isolation_level="AUTOCOMMIT"
+    )
+    drop = text(f'DROP DATABASE IF EXISTS "{url.database}" WITH (FORCE)')
+    with maintenance.connect() as connection:
+        connection.execute(drop)
+        connection.execute(text(f'CREATE DATABASE "{url.database}"'))
+
+    SQLModel.metadata.create_all(engine)
     with Session(engine) as session:
         init_db(session)
         yield session
-        statement = delete(User)
-        session.execute(statement)
-        session.commit()
+
+    engine.dispose()
+    with maintenance.connect() as connection:
+        connection.execute(drop)
+    maintenance.dispose()
 
 
 @pytest.fixture(scope="module")