feat(auth): M2 占用响应加 conflict_ticket/has_wechat/rebind_available

Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>

app/api/v1/auth.py

@@ -20,7 +20,9 @@ from app.core.ratelimit import enforce_rate_limit
 from app.core.security import (
     TokenError,
     create_bind_ticket,
+    create_conflict_ticket,
     decode_bind_ticket,
+    decode_conflict_ticket,
     decode_token,
     issue_token_pair,
 )
@@ -28,6 +30,7 @@ from app.integrations import wxpay
 from app.integrations.jiguang import JiguangError, mask_phone, verify_and_get_phone
 from app.integrations.sms import SmsError, send_code, verify_code
 from app.repositories import onboarding as onboarding_repo
+from app.repositories import phone_rebind as rebind_repo
 from app.repositories import user as user_repo
 from app.schemas.auth import (
     JverifyLoginRequest,
@@ -240,13 +243,32 @@ def _finish_wechat_bind(
     未占用 → 新建微信账号(channel=wechat,昵称头像取微信)→ 签 token 登入。"""
     existing = user_repo.get_user_by_phone(db, phone)
     if existing is not None:
-        logger.info("wechat bind phone occupied phone=%s by user_id=%d", mask_phone(phone), existing.id)
+        from app.core.config import settings  # 局部 import,避免循环
+
+        ticket = create_conflict_ticket(
+            openid=openid,
+            wechat_nickname=wechat_nickname,
+            wechat_avatar_url=wechat_avatar_url,
+            phone=phone,
+        )
+        blocked = rebind_repo.rebound_within_days(db, phone, settings.PHONE_REBIND_LIMIT_DAYS)
+        logger.info(
+            "wechat bind phone occupied phone=%s by user_id=%d has_wechat=%s",
+            mask_phone(phone), existing.id, bool(existing.wechat_openid),
+        )
         return WechatBindResultResponse(
             status="phone_occupied",
             occupied_account=OccupiedAccountInfo(
                 nickname=existing.nickname,
                 avatar_url=existing.avatar_url,
                 created_at=existing.created_at,
+                has_wechat=bool(existing.wechat_openid),
+            ),
+            conflict_ticket=ticket,
+            rebind_available=not blocked,
+            rebind_blocked_days=(
+                rebind_repo.remaining_block_days(db, phone, settings.PHONE_REBIND_LIMIT_DAYS)
+                if blocked else 0
             ),
         )
     user = user_repo.create_wechat_user(