feat(debug-trace): 调试链接权限 + trace_url 落库与按权限下发 (#35)

- user 加 debug_trace_enabled、comparison_record 加 trace_url
- 迁移 f8d3b1e60a27：加两列，down_revision 用 tuple 顺带合并既存双 head(invite_fingerprint_table + 044dce6e9b1f)
- UserOut 加 debug_trace_enabled → /me 与登录响应带出
- ComparisonRecordIn/Out 加 trace_url；upsert 落库
- /compare/records 列表与详情按 user.debug_trace_enabled 下发；详情连 raw_payload 里那份一并抹掉，防权限绕过
- admin 加 POST /users/{id}/debug-trace（operator + 审计），列表带该字段

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>

Reviewed-on: #35

app/api/v1/compare_record.py

@@ -77,10 +77,12 @@ def list_records(
     items, next_cursor = crud_compare.list_records(
         db, user.id, limit=limit, cursor=cursor
     )
-    return ComparisonRecordPage(
-        items=[ComparisonRecordOut.model_validate(it) for it in items],
-        next_cursor=next_cursor,
-    )
+    outs = [ComparisonRecordOut.model_validate(it) for it in items]
+    # 权限闸:未开 debug_trace_enabled 的用户不下发 trace_url(列表页「复制调试链接」靠它)
+    if not user.debug_trace_enabled:
+        for o in outs:
+            o.trace_url = None
+    return ComparisonRecordPage(items=outs, next_cursor=next_cursor)
 
 
 @router.get(
@@ -94,4 +96,12 @@ def get_record(
     rec = crud_compare.get_record(db, user.id, record_id)
     if rec is None:
         raise HTTPException(status_code=status.HTTP_404_NOT_FOUND, detail="record not found")
-    return ComparisonRecordDetailOut.model_validate(rec)
+    out = ComparisonRecordDetailOut.model_validate(rec)
+    # 权限闸:未开 debug_trace_enabled 的用户不下发 trace_url。
+    # ⚠️ raw_payload 是上报体全量(model_dump),里面也藏着一份 trace_url,必须一并抹掉——
+    # 否则无权限用户从详情接口的 raw_payload 绕过权限闸拿到 trace_url。
+    if not user.debug_trace_enabled:
+        out.trace_url = None
+        if isinstance(out.raw_payload, dict):
+            out.raw_payload.pop("trace_url", None)
+    return out