feat: wechat group+member and talker scrapers

Add scrape_wechat_groups (POST /wechatweb/chatroom/getChatroomList) and
scrape_wechat_talkers (POST /wechatweb/wxFriends/talkerList), both reusing
the page-number paginator. Groups parse the semicolon-joined memberIds into
a member_ids_list so upsert_chat_group can mirror GroupMember rows
(composite PK channel/room_id/member_id) idempotently alongside the
ChatGroup row. Talkers are a sync-planning input (member_count>0 marks a
group conversation); no dedicated table.

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

yunke-server/app/storage/repos.py

@@ -48,9 +48,18 @@ import sqlalchemy as sa
 from sqlalchemy.ext.asyncio import AsyncSession
 from sqlalchemy.orm import DeclarativeBase
 
-from app.db.models import Customer, Department, Message, Staff, WechatAccount
+from app.db.models import (
+    ChatGroup,
+    Customer,
+    Department,
+    GroupMember,
+    Message,
+    Staff,
+    WechatAccount,
+)
 
 __all__ = [
+    "upsert_chat_group",
     "upsert_customer",
     "upsert_customers",
     "upsert_department",
@@ -383,3 +392,54 @@ async def upsert_staff_from_account(session: AsyncSession, rec: dict[str, Any])
         if key in rec:
             staff_rec[key] = rec[key]
     await upsert_staff(session, staff_rec)
+
+
+# ---------------------------------------------------------------------------
+# ChatGroup + GroupMember upsert (M2)
+# ---------------------------------------------------------------------------
+
+
+async def upsert_chat_group(session: AsyncSession, rec: dict[str, Any]) -> None:
+    """Idempotently upsert one :class:`ChatGroup` AND its :class:`GroupMember` rows.
+
+    PK = ``room_id``. The group row is upserted first; then, for every id in
+    the record's ``member_ids_list`` (the scraper-parsed, empties-dropped
+    member wxid list), a :class:`GroupMember` row is upserted against the
+    composite PK ``(channel, room_id, member_id)``. Re-scraping a group
+    therefore refreshes the group row and re-asserts its members without
+    duplication (idempotent).
+
+    The ``member_ids_list`` key is the parsed list shape produced by
+    :func:`app.scraper.wechat._normalize_chat_group`; it is NOT a
+    ``ChatGroup`` column, so it is dropped by :func:`_build_column_values`
+    when writing the group row (the raw semicolon-joined string is preserved
+    on ``ChatGroup.member_ids``).
+
+    Per-member ``nickname`` / ``avatar`` / ``display_name`` are left ``None``
+    here — Phase-0 does not yet resolve them (they need a separate per-member
+    API; see data dictionary §9.6). The repo writes a minimal member row keyed
+    by the composite PK so membership is captured now and enriched later.
+    """
+    await _upsert_one(session, ChatGroup, rec)
+
+    channel = rec.get("channel") or "wechat"
+    room_id = rec.get("room_id")
+    # No room_id -> nothing to key member rows on (defensive; the scraper
+    # always sets room_id). Skip the member loop rather than raising so a
+    # malformed record still lands its (PK-less) group upsert attempt above.
+    if not room_id:
+        return
+
+    member_ids: list[Any] = list(rec.get("member_ids_list") or [])
+    for member_id in member_ids:
+        # Defensive: never insert an empty/falsy member id (would collide on
+        # an empty-PK row). The scraper already drops empties, but a hand-
+        # built record could slip one through.
+        if not member_id:
+            continue
+        member_rec: dict[str, Any] = {
+            "channel": channel,
+            "room_id": room_id,
+            "member_id": member_id,
+        }
+        await _upsert_one(session, GroupMember, member_rec)