refactor(routes): 搬遷 sales 實作並刪除 app.py 重複路由

ADR-017 Phase 3f-1 sales sprint；sales_bp 改為真實實作，移除 app.py 7 條 sales duplicate route，保留 /growth_analysis Blueprint 版。

routes/export_routes.py

@@ -583,7 +583,7 @@ def export_vendor_analysis():
         else:
             params = {k: v for k, v in request.args.items()}
             flash('資料快取已失效，請稍候重新載入資料後再匯出。', 'warning')
-            return redirect(url_for('sales_analysis', **params))
+            return redirect(url_for('sales.sales_analysis', **params))
 
         col_vendor = cols_map.get('vendor')
         col_amount = cols_map.get('amount')