refactor: break up capture_error() into testable helpers

Extract 5 focused helpers from the 138-line capture_error():
- _extract_origin(): walk traceback for file/line
- _log_error_event(): log to event log (best-effort)
- _create_bug_report(): create task and log creation event
- _send_error_notification(): push notification
- _record_to_session(): forward to session recorder

capture_error() now orchestrates the helpers in ~25 lines.
Added tests for each new helper.

Fixes #506

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

src/infrastructure/error_capture.py

@@ -100,48 +100,25 @@ def _get_git_context() -> dict:
         return {"branch": "unknown", "commit": "unknown"}
 
 
-def capture_error(
-    exc: Exception,
-    source: str = "unknown",
-    context: dict | None = None,
-) -> str | None:
-    """Capture an error and optionally create a bug report.
-
-    Args:
-        exc: The exception to capture
-        source: Module/component where the error occurred
-        context: Optional dict of extra context (request path, etc.)
-
-    Returns:
-        Task ID of the created bug report, or None if deduplicated/disabled
-    """
-    from config import settings
-
-    if not settings.error_feedback_enabled:
-        return None
-
-    error_hash = _stack_hash(exc)
-
-    if _is_duplicate(error_hash):
-        logger.debug("Duplicate error suppressed: %s (hash=%s)", exc, error_hash)
-        return None
-
-    # Format the stack trace
-    tb_str = "".join(traceback.format_exception(type(exc), exc, exc.__traceback__))
-
-    # Extract file/line from traceback
+def _extract_origin(exc: Exception) -> tuple[str, int]:
+    """Walk the traceback to find the deepest file and line number."""
     tb_obj = exc.__traceback__
-    affected_file = "unknown"
-    affected_line = 0
     while tb_obj and tb_obj.tb_next:
         tb_obj = tb_obj.tb_next
     if tb_obj:
-        affected_file = tb_obj.tb_frame.f_code.co_filename
-        affected_line = tb_obj.tb_lineno
+        return tb_obj.tb_frame.f_code.co_filename, tb_obj.tb_lineno
+    return "unknown", 0
 
-    git_ctx = _get_git_context()
 
-    # 1. Log to event_log
+def _log_error_event(
+    exc: Exception,
+    source: str,
+    error_hash: str,
+    affected_file: str,
+    affected_line: int,
+    git_ctx: dict,
+) -> None:
+    """Log the error to the event log (best-effort)."""
     try:
         from swarm.event_log import EventType, log_event
 
@@ -161,8 +138,18 @@ def capture_error(
     except Exception as log_exc:
         logger.debug("Failed to log error event: %s", log_exc)
 
-    # 2. Create bug report task
-    task_id = None
+
+def _create_bug_report(
+    exc: Exception,
+    source: str,
+    error_hash: str,
+    affected_file: str,
+    affected_line: int,
+    git_ctx: dict,
+    tb_str: str,
+    context: dict | None,
+) -> str | None:
+    """Create a bug report task and return its ID (best-effort)."""
     try:
         from swarm.task_queue.models import create_task
 
@@ -193,29 +180,30 @@ def capture_error(
             auto_approve=True,
             task_type="bug_report",
         )
-        task_id = task.id
 
-        # Log the creation event
         try:
             from swarm.event_log import EventType, log_event
 
             log_event(
                 EventType.BUG_REPORT_CREATED,
                 source=source,
-                task_id=task_id,
+                task_id=task.id,
                 data={
                     "error_hash": error_hash,
                     "title": title[:100],
                 },
             )
-        except Exception as exc:
-            logger.warning("Bug report screenshot error: %s", exc)
-            pass
+        except Exception as log_exc:
+            logger.warning("Bug report log error: %s", log_exc)
 
+        return task.id
     except Exception as task_exc:
         logger.debug("Failed to create bug report task: %s", task_exc)
+        return None
 
-    # 3. Send notification
+
+def _send_error_notification(exc: Exception, source: str) -> None:
+    """Push a notification about the captured error (best-effort)."""
     try:
         from infrastructure.notifications.push import notifier
 
@@ -224,11 +212,12 @@ def capture_error(
             message=f"{type(exc).__name__} in {source}: {str(exc)[:80]}",
             category="system",
         )
-    except Exception as exc:
-        logger.warning("Bug report notification error: %s", exc)
-        pass
+    except Exception as notify_exc:
+        logger.warning("Bug report notification error: %s", notify_exc)
 
-    # 4. Record in session logger (via registered callback)
+
+def _record_to_session(exc: Exception, source: str) -> None:
+    """Forward the error to the registered session recorder (best-effort)."""
     if _error_recorder is not None:
         try:
             _error_recorder(
@@ -238,4 +227,44 @@ def capture_error(
         except Exception as log_exc:
             logger.warning("Bug report session logging error: %s", log_exc)
 
+
+def capture_error(
+    exc: Exception,
+    source: str = "unknown",
+    context: dict | None = None,
+) -> str | None:
+    """Capture an error and optionally create a bug report.
+
+    Args:
+        exc: The exception to capture
+        source: Module/component where the error occurred
+        context: Optional dict of extra context (request path, etc.)
+
+    Returns:
+        Task ID of the created bug report, or None if deduplicated/disabled
+    """
+    from config import settings
+
+    if not settings.error_feedback_enabled:
+        return None
+
+    error_hash = _stack_hash(exc)
+
+    if _is_duplicate(error_hash):
+        logger.debug("Duplicate error suppressed: %s (hash=%s)", exc, error_hash)
+        return None
+
+    tb_str = "".join(traceback.format_exception(type(exc), exc, exc.__traceback__))
+    affected_file, affected_line = _extract_origin(exc)
+    git_ctx = _get_git_context()
+
+    _log_error_event(exc, source, error_hash, affected_file, affected_line, git_ctx)
+
+    task_id = _create_bug_report(
+        exc, source, error_hash, affected_file, affected_line, git_ctx, tb_str, context
+    )
+
+    _send_error_notification(exc, source)
+    _record_to_session(exc, source)
+
     return task_id