fix(chat): 解析 XML 的 cdn 链接时进行反转义

- 新增 _normalize_xml_url 统一处理 & 等转义字符
- 图片/视频/表情消息的 cdn URL 解析统一规范化，避免误判为 file_id

src/wechat_decrypt_tool/chat_helpers.py

@@ -530,6 +530,17 @@ def _strip_cdata(s: str) -> str:
     return out.strip()
 
 
+def _normalize_xml_url(url: str) -> str:
+    """Normalize URLs extracted from XML attributes/tags (e.g. decode '&')."""
+    u = str(url or "").strip()
+    if not u:
+        return ""
+    try:
+        return html.unescape(u).strip()
+    except Exception:
+        return u.replace("&", "&").strip()
+
+
 def _extract_xml_tag_text(xml_text: str, tag: str) -> str:
     if not xml_text or not tag:
         return ""

src/wechat_decrypt_tool/routers/chat.py

@@ -33,6 +33,7 @@ from ..chat_helpers import (
     _load_contact_rows,
     _load_latest_message_previews,
     _lookup_resource_md5,
+    _normalize_xml_url,
     _parse_app_message,
     _parse_pat_message,
     _pick_avatar_url,
@@ -481,8 +482,10 @@ def _append_full_messages_from_rows(
                 or _extract_xml_tag_text(raw_text, "cdnmidimgurl")
                 or _extract_xml_tag_text(raw_text, "cdnbigimgurl")
             )
-            _cdn_url_or_id = str(_cdn_url_or_id or "").strip()
+            _cdn_url_or_id = _normalize_xml_url(_cdn_url_or_id)
-            image_url = _cdn_url_or_id if _cdn_url_or_id.startswith(("http://", "https://")) else ""
+            image_url = (
+                _cdn_url_or_id if str(_cdn_url_or_id).lower().startswith(("http://", "https://")) else ""
+            )
             if (not image_url) and _cdn_url_or_id:
                 image_file_id = _cdn_url_or_id
 
@@ -512,6 +515,9 @@ def _append_full_messages_from_rows(
                 raw_text, "cdnvideourl"
             )
 
+            video_thumb_url_or_id = _normalize_xml_url(video_thumb_url_or_id)
+            video_url_or_id = _normalize_xml_url(video_url_or_id)
+
             video_thumb_url = (
                 video_thumb_url_or_id
                 if str(video_thumb_url_or_id or "").strip().lower().startswith(("http://", "https://"))
@@ -542,6 +548,7 @@ def _append_full_messages_from_rows(
             emoji_url = _extract_xml_attr(raw_text, "cdnurl")
             if not emoji_url:
                 emoji_url = _extract_xml_tag_text(raw_text, "cdn_url")
+            emoji_url = _normalize_xml_url(emoji_url)
             if (not emoji_md5) and resource_conn is not None:
                 emoji_md5 = _lookup_resource_md5(
                     resource_conn,