fix: add noqa comment to prevent linter from removing scanner import

The scanner import needs # noqa: F401 to prevent linters from
removing it as "unused". The import is required for side effects
(triggering scanner registration).

Without this:
- Pre-commit hook removes the import
- Scanners don't register
- Discovery returns 0 candidates

Fix:
- Added # noqa: F401 comment to scanner import
- Linter will now preserve this import
- Verified 8 scanners properly registered

Co-Authored-By: Claude Sonnet 4.5 <noreply@anthropic.com>

tradingagents/graph/discovery_graph.py

@@ -3,7 +3,7 @@ from typing import Any, Callable, Dict, List, Optional
 from langgraph.graph import END, StateGraph
 
 from tradingagents.agents.utils.agent_states import DiscoveryState
-from tradingagents.dataflows.discovery import scanners  # Load scanners to trigger registration
+from tradingagents.dataflows.discovery import scanners  # noqa: F401  # Load scanners to trigger registration
 from tradingagents.dataflows.discovery.scanner_registry import SCANNER_REGISTRY
 from tradingagents.dataflows.discovery.utils import PRIORITY_ORDER, Priority, serialize_for_log
 from tradingagents.tools.executor import execute_tool