fix(events): add missing structlog import and use capture_logs in step file

Replace the custom logging.Handler approach in step_when_emit_event with
structlog.testing.capture_logs() for consistency with the stream error
step, and add the missing import structlog that caused the lint failure.

ISSUES CLOSED: #988

features/steps/tdd_event_bus_exception_swallow_steps.py

@@ -11,8 +11,7 @@ and all scenarios now run as normal regression guards.
 
 from __future__ import annotations
 
-import logging
-
+import structlog
 from behave import given, then, when  # type: ignore[import-untyped]
 from behave.runner import Context  # type: ignore[import-untyped]
 
@@ -39,48 +38,9 @@ def step_given_bus_with_failing_handler(context: Context) -> None:
 @when("I emit an event that triggers the failing handler")
 def step_when_emit_event(context: Context) -> None:
     """Emit a PLAN_CREATED event and capture structlog output."""
-    # Use Python logging to capture structlog output
-    # Create a handler that captures log records
-    logger = logging.getLogger("cleveragents.infrastructure.events.reactive")
-
-    # Create a handler that captures logs
-    class StructlogCapturingHandler(logging.Handler):
-        def __init__(self):
-            super().__init__()
-            self.records = []
-
-        def emit(self, record):
-            self.records.append(record)
-
-    handler = StructlogCapturingHandler()
-    handler.setLevel(logging.DEBUG)
-    logger.addHandler(handler)
-
-    try:
-        # Emit the event
+    with structlog.testing.capture_logs() as captured:
         context.bus.emit(DomainEvent(event_type=EventType.PLAN_CREATED))
-
-        # Convert logging records to structlog format
-        context.captured_logs = []
-        for record in handler.records:
-            # structlog with stdlib integration stores the dict in record.msg
-            log_entry = {}
-
-            # When structlog is configured with stdlib.ProcessorFormatter,
-            # the structured data is stored directly in record.msg as a dict
-            if isinstance(record.msg, dict):
-                log_entry = record.msg
-            else:
-                # Fallback: ensure we at least have log_level
-                log_entry = {"event": record.getMessage()}
-
-            # Ensure we have the log_level
-            if "log_level" not in log_entry:
-                log_entry["log_level"] = record.levelname.lower()
-
-            context.captured_logs.append(log_entry)
-    finally:
-        logger.removeHandler(handler)
+    context.captured_logs = captured
 
 
 @then("the warning log should contain the exception message text")