chore: fix all ruff lint warnings

- Remove unused datetime imports from openbb_service, market_service,
  quantitative_service (now using obb_utils.days_ago)
- Remove unused variable 'maintains' in routes_sentiment
- Remove unused imports in test files
- Fix forward reference annotation in test helper

market_service.py

@@ -2,7 +2,6 @@
 
 import asyncio
 import logging
-from datetime import datetime, timezone, timedelta
 from typing import Any
 
 from openbb import obb

openbb_service.py

@@ -1,6 +1,5 @@
 import asyncio
 import logging
-from datetime import datetime, timedelta, timezone
 from typing import Any
 
 import yfinance as yf

quantitative_service.py

@@ -2,7 +2,6 @@
 
 import asyncio
 import logging
-from datetime import datetime, timezone, timedelta
 from typing import Any
 
 from openbb import obb

routes_sentiment.py

@@ -76,7 +76,6 @@ async def stock_sentiment(symbol: str = Path(..., min_length=1, max_length=20)):
     if isinstance(upgrades_data, list) and upgrades_data:
         ups = sum(1 for u in upgrades_data if u.get("action") in ("up", "init"))
         downs = sum(1 for u in upgrades_data if u.get("action") == "down")
-        maintains = len(upgrades_data) - ups - downs
         if len(upgrades_data) > 0:
             upgrade_score = (ups - downs) / len(upgrades_data)
             scores.append(("upgrades", round(upgrade_score, 3), 0.20))

tests/test_akshare_service.py

@@ -1,7 +1,6 @@
 """Unit tests for akshare_service.py - written FIRST (TDD RED phase)."""
 
-from datetime import datetime
+from unittest.mock import patch
-from unittest.mock import MagicMock, patch
 
 import pandas as pd
 import pytest

tests/test_defi_service.py

@@ -7,7 +7,6 @@ from unittest.mock import AsyncMock, MagicMock, patch
 
 import pytest
 
-import defi_service
 from defi_service import (
     get_chain_tvls,
     get_dex_volumes,

tests/test_portfolio_service.py

@@ -268,7 +268,7 @@ async def test_fetch_historical_prices_skips_none(mock_fetch_hist):
 # ---------------------------------------------------------------------------
 
 
-def _make_prices(symbols: list[str], n_days: int = 60) -> "pd.DataFrame":
+def _make_prices(symbols: list[str], n_days: int = 60):
     """Build a deterministic price DataFrame with enough rows for t-SNE."""
     import numpy as np
     import pandas as pd
@@ -383,7 +383,6 @@ async def test_cluster_stocks_no_data_raises(mock_fetch):
 @patch("portfolio_service.fetch_historical_prices", new_callable=AsyncMock)
 async def test_cluster_stocks_identical_returns_still_works(mock_fetch):
     """t-SNE should not raise even when all symbols have identical returns."""
-    import numpy as np
     import pandas as pd
     import portfolio_service
 
@@ -530,7 +529,6 @@ async def test_find_similar_stocks_no_data_raises(mock_fetch):
 @patch("portfolio_service.fetch_historical_prices", new_callable=AsyncMock)
 async def test_find_similar_stocks_target_not_in_data_raises(mock_fetch):
     """find_similar_stocks raises ValueError when target symbol has no data."""
-    import pandas as pd
     import portfolio_service
 
     # Only universe symbols have data, not the target