fix: 物流表格识别优先用阿里云OCR，SDK不可用时降级LLM视觉

拆分为三种方法：_parse_table_via_ocr（OCR+LLM）、
_parse_table_via_llm_vision（LLM视觉直读），
自动检测SDK可用性选择路径。

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

backend/app/services/order_service.py

@@ -2400,15 +2400,61 @@ class OrderService:
 
 
     def parse_logistics_table_images(self, image_urls, session):
-        """识别物流表格截图，用 LLM 视觉能力直接从图片中提取快递单号和收件人。"""
+        """识别物流表格截图。优先用阿里云OCR+LLM，SDK不可用时降级为LLM视觉直接识别。"""
+        import logging as _log
+        _logger = _log.getLogger(__name__)
+
+        # 检测阿里云 OCR SDK 是否可用
+        try:
+            from alibabacloud_ocr_api20210707.models import RecognizeGeneralRequest  # noqa: F401
+            ocr_available = True
+        except ImportError:
+            ocr_available = False
+            _logger.info("[parse_logistics_table_images] 阿里云OCR SDK未安装，将使用LLM视觉识别")
+
+        if ocr_available:
+            return self._parse_table_via_ocr(image_urls, session, _logger)
+        return self._parse_table_via_llm_vision(image_urls, _logger)
+
+    def _parse_table_via_ocr(self, image_urls, session, _logger):
+        """阿里云OCR + LLM提取。"""
+        from backend.app.services.ai_service import ai_service
+        from backend.app.core.config import get_settings
+        settings = get_settings()
+        results = []
+        seen_tracking = set()
+        for url in image_urls:
+            try:
+                _logger.info("[parse_logistics_table_images] OCR处理图片: %s", url)
+                ctx = ai_service._ocr_and_parse_image(url)
+                raw_text = ctx.get("raw_text", "")
+                _logger.info("[parse_logistics_table_images] OCR文本长度: %d", len(raw_text))
+                if not raw_text.strip():
+                    continue
+                llm_items = self._llm_extract_logistics(raw_text, settings)
+                for item in llm_items:
+                    tn = (item.get("tracking_number") or "").strip()
+                    if not tn or len(tn) < 10 or tn in seen_tracking:
+                        continue
+                    seen_tracking.add(tn)
+                    results.append({
+                        "tracking_number": tn,
+                        "express_company": item.get("express_company") or None,
+                        "recipient_name": item.get("recipient_name") or None,
+                    })
+            except Exception as exc:
+                _logger.warning("[parse_logistics_table_images] OCR识别失败: %s", exc, exc_info=True)
+        _logger.info("[parse_logistics_table_images] OCR模式最终结果: %d条", len(results))
+        return results
+
+    def _parse_table_via_llm_vision(self, image_urls, _logger):
+        """LLM视觉直接识别表格图片。"""
         import base64 as _b64
         import json as _json
-        import logging as _log
         from urllib import request as urllib_request
         from backend.app.services.ai_service import read_image_bytes
         from backend.app.core.config import get_settings
 
-        _logger = _log.getLogger(__name__)
         settings = get_settings()
         api_key = settings.llm_parse_api_key or settings.aliyun_ai_access_key_id
 
@@ -2425,7 +2471,7 @@ class OrderService:
         seen_tracking = set()
         for url in image_urls:
             try:
-                _logger.info("[parse_logistics_table_images] 处理图片: %s", url)
+                _logger.info("[parse_logistics_table_images] LLM视觉处理图片: %s", url)
                 image_bytes = read_image_bytes(url)
                 image_b64 = _b64.b64encode(image_bytes).decode("utf-8")
                 suffix = url.rsplit(".", 1)[-1].lower() if "." in url else "jpeg"
@@ -2455,7 +2501,6 @@ class OrderService:
                 content = result["choices"][0]["message"]["content"]
                 _logger.info("[parse_logistics_table_images] LLM响应: %s", content[:500])
                 llm_items = self._extract_json_array(content)
-                _logger.info("[parse_logistics_table_images] 提取结果: %d条", len(llm_items))
 
                 for item in llm_items:
                     tn = (item.get("tracking_number") or "").strip()
@@ -2468,8 +2513,8 @@ class OrderService:
                         "recipient_name": item.get("recipient_name") or None,
                     })
             except Exception as exc:
-                _logger.warning("[parse_logistics_table_images] 识别失败: %s", exc, exc_info=True)
-        _logger.info("[parse_logistics_table_images] 最终结果: %d条", len(results))
+                _logger.warning("[parse_logistics_table_images] LLM视觉识别失败: %s", exc, exc_info=True)
+        _logger.info("[parse_logistics_table_images] LLM视觉模式最终结果: %d条", len(results))
         return results
 
     def _llm_extract_logistics(self, text, settings):