feat(chat): 聊天排版升级微信标准(左右分侧+头像+绿气泡)+is_send数据修复

- is_send 根因:云客消息方向在 mine 字段(isSend 全 null),归一化加 fallback
  +存量回填 60.7 万行(51万收/16万发)——分侧数据首次完整
- MessageBubble:头像(对方=raw headUrl 在左/自己=默认在右)、自己侧隐藏昵称、
  接收白底描边/发送微信绿 #95ec69、气泡列 max-width 78%
- 实测混合对话:13发(绿+头像右)/7收(白+头像左)全部正确

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

yunke-server/scripts/scrape_via_page.py

@@ -655,7 +655,10 @@ async def scrape_messages(cookie_str: str, max_conversations: int = 100):
                             # 用发送的 friend_id（与客户表一致）优先，API 返回的 talker 可能脱敏
                             "talker_id": friend_id or row.get("talker") or row.get("oriTalker"),
                             "room_id": None,
-                            "is_send": bool(row.get("isSend", 0)) if row.get("isSend") is not None else None,
+                            "is_send": (
+                                bool(row["isSend"]) if row.get("isSend") is not None
+                                else (bool(row["mine"]) if row.get("mine") is not None else None)
+                            ),
                             "type": _normalize_msg_type(row.get("type")),
                             "type_raw": row.get("type"),
                             "text": row.get("content") or row.get("text") or "",
@@ -744,7 +747,10 @@ def _normalize_group_message(row: dict, owner_id: str, room_id: str) -> dict | N
         "owner_account_id": owner_id,
         "talker_id": talker or None,
         "room_id": row.get("roomid") or room_id,
-        "is_send": bool(row.get("isSend", 0)) if row.get("isSend") is not None else None,
+        "is_send": (
+                                bool(row["isSend"]) if row.get("isSend") is not None
+                                else (bool(row["mine"]) if row.get("mine") is not None else None)
+                            ),
         "type": _normalize_msg_type(row.get("type")),
         "type_raw": row.get("type"),
         "text": row.get("content") or row.get("text") or "",