fix(api): query 接口 Decimal 输出去掉存储尺度尾零

Fact 金额字段是 DecimalField(max_digits=44, decimal_places=24)，PostgreSQL
把 NUMERIC(44,24) 原样读回，/api/query 的 JsonResponse 对 Decimal 直接
str()，把 24 位存储尺度尾零（如 1000.000000000000000000000000）暴露给
前端与 e2e；SQLite 无此尺度所以本地从未复现（formula-export e2e 在
run 1959/1961 失败的直接原因）。

复用 evidence 接口既有的 amount_text 归一化，新增 AmountJSONEncoder
只覆盖 Decimal 分支；assistant 等内部消费 analyze() 的路径仍拿到
Decimal，不受影响。前端所有数值都经 Number()/format() 解析，格式变化
透明。新增单测锁定 encoder 行为及 /api/query 汇总值输出。

finance/views.py

@@ -7,6 +7,7 @@ import math
 import tempfile
 import uuid
 from datetime import timedelta
+from decimal import Decimal
 from functools import wraps
 from pathlib import Path
 
@@ -15,6 +16,7 @@ from django.contrib.auth import authenticate, login, logout
 from django.contrib.auth.models import User
 from django.contrib.auth.password_validation import validate_password
 from django.core.exceptions import ValidationError
+from django.core.serializers.json import DjangoJSONEncoder
 from django.db import IntegrityError, connection, transaction
 from django.http import FileResponse, HttpResponse, JsonResponse
 from django.middleware.csrf import get_token
@@ -294,7 +296,7 @@ def query(request, dataset_id):
     ds = dataset(request, dataset_id, True)
     pref, _ = preferences(request, ds)
     limit(f"analysis:{request.user.pk}", 120, 60)
-    return JsonResponse(analyze(ds, request.member, body(request), pref))
+    return JsonResponse(analyze(ds, request.member, body(request), pref), encoder=AmountJSONEncoder)
 
 
 def amount_text(value):
@@ -305,6 +307,19 @@ def amount_text(value):
     return "0" if text == "-0" else text
 
 
+class AmountJSONEncoder(DjangoJSONEncoder):
+    """分析接口的 Decimal 统一经 amount_text 输出。
+
+    PostgreSQL 把 NUMERIC(44,24) 原样读回，DjangoJSONEncoder 默认 str() 会把
+    存储尺度尾零直接暴露给前端；SQLite 无此尺度，两库表现需一致。
+    """
+
+    def default(self, o):
+        if isinstance(o, Decimal):
+            return amount_text(o)
+        return super().default(o)
+
+
 @endpoint(("POST",))
 def evidence(request, dataset_id):
     ds = dataset(request, dataset_id, True)

tests/test_finance.py

@@ -192,6 +192,34 @@ def test_evidence_amounts_trim_storage_scale(workspace):
     assert row["gross"] == "50"
 
 
+def test_query_amounts_trim_storage_scale(workspace):
+    from decimal import Decimal
+
+    from finance.views import AmountJSONEncoder
+
+    assert (
+        AmountJSONEncoder().encode({"current": Decimal("1000.000000000000000000000000")})
+        == '{"current": "1000"}'
+    )
+
+    ds, _, client, *_ = workspace
+    response = client.post(
+        f"/api/datasets/{ds.pk}/query",
+        data={
+            "start": "2026-08",
+            "end": "2026-08",
+            "comparison": "yoy",
+            "group": "department",
+            "metric": "revenue",
+        },
+        content_type="application/json",
+    )
+    assert response.status_code == 200
+    summary = response.json()["summary"]
+    assert summary["revenue"]["current"] == "90"
+    assert summary["revenue"]["baseline"] == "150"
+
+
 def test_settings_revision_and_invalid_metric_are_rejected(workspace):
     ds, _, client, *_ = workspace
     url = f"/api/datasets/{ds.pk}/settings"