fix: optimize summary count query and refine row keys for external api logs

backend/app/routers/external_api_logs.py

@@ -85,13 +85,15 @@ def get_external_api_log_summary(
     slow_ms: Optional[int] = Query(None),
     hours: int = Query(24, ge=1, le=720),
     limit: int = Query(50, ge=1, le=200),
+    offset: int = Query(0, ge=0),
     db: Session = Depends(get_db),
     _=Depends(get_current_user),
 ):
     """Return aggregated summary grouped by direction + target + method + path.
 
-    - hours: time window (default 24, max 720).  None means no time filter.
+    - hours: time window (default 24, max 720).
     - limit: max rows returned (default 50, max 200).
+    - offset: pagination offset (default 0).
     """
     settings = get_settings()
     slow_threshold = slow_ms if slow_ms is not None else settings.external_api_log_slow_ms
@@ -107,7 +109,7 @@ def get_external_api_log_summary(
         ExternalApiLog.method,
         ExternalApiLog.path,
     ).order_by(func.sum(ExternalApiLog.duration_ms).desc())
-    q = q.limit(limit)
+    q = q.offset(offset).limit(limit)
     rows = q.all()
 
     return [
@@ -129,6 +131,42 @@ def get_external_api_log_summary(
     ]
 
 
+@router.get("/summary/count")
+def count_external_api_log_summary(
+    slow_ms: Optional[int] = Query(None),
+    hours: int = Query(24, ge=1, le=720),
+    db: Session = Depends(get_db),
+    _=Depends(get_current_user),
+):
+    """Return the number of distinct aggregated summary groups.
+
+    Uses the same grouping as /summary, returns the count of groups
+    (not the count of raw log rows).
+    """
+    settings = get_settings()
+    slow_threshold = slow_ms if slow_ms is not None else settings.external_api_log_slow_ms
+
+    q = db.query(
+        ExternalApiLog.direction,
+        ExternalApiLog.target_type,
+        ExternalApiLog.target_id,
+        ExternalApiLog.target_name,
+        ExternalApiLog.method,
+        ExternalApiLog.path,
+    )
+    cutoff = datetime.now(timezone.utc) - timedelta(hours=hours)
+    q = q.filter(ExternalApiLog.created_at >= cutoff)
+    q = q.group_by(
+        ExternalApiLog.direction,
+        ExternalApiLog.target_type,
+        ExternalApiLog.target_id,
+        ExternalApiLog.target_name,
+        ExternalApiLog.method,
+        ExternalApiLog.path,
+    )
+    return {"total": q.count()}
+
+
 def _summary_cols(slow_threshold: int) -> list:
     return [
         ExternalApiLog.direction,