Phase 0.1: Remove backend deprecated code

- Delete routes: counter.py, sum.py
- Delete jobs.py and worker.py
- Delete tests: test_counter.py, test_jobs.py
- Update audit.py: keep only price-history endpoints
- Update models.py: remove VIEW_COUNTER, INCREMENT_COUNTER, USE_SUM permissions
- Update models.py: remove Counter, SumRecord, CounterRecord, RandomNumberOutcome models
- Update schemas.py: remove sum/counter related schemas
- Update main.py: remove deleted router imports
- Update test_permissions.py: remove tests for deprecated features
- Update test_price_history.py: remove worker-related tests
- Update conftest.py: remove mock_enqueue_job fixture
- Update auth.py: fix example in docstring

backend/tests/conftest.py

@@ -1,6 +1,5 @@
 import os
 from contextlib import asynccontextmanager
-from unittest.mock import AsyncMock, patch
 
 # Set required env vars before importing app
 os.environ.setdefault("SECRET_KEY", "test-secret-key-for-testing-only")
@@ -239,18 +238,3 @@ async def user_no_roles(client_factory):
         "cookies": dict(response.cookies),
         "response": response,
     }
-
-
-@pytest.fixture
-def mock_enqueue_job():
-    """Mock job enqueueing for tests that hit the counter increment endpoint.
-
-    pgqueuer requires PostgreSQL-specific features that aren't available
-    in the test database setup. We mock the enqueue function to avoid
-    connection issues while still testing the counter logic.
-
-    Tests that call POST /api/counter/increment must use this fixture.
-    """
-    mock = AsyncMock(return_value=1)  # Return a fake job ID
-    with patch("routes.counter.enqueue_random_number_job", mock):
-        yield mock