feat: 完善预算中心图表与确认对话框交互

后端预算服务增加汇总查询和辅助计算，前端预算中心优化趋
势图组件和数据展示，增强确认对话框通用性和样式，完善预
算编辑对话框布局，补充预算端点单元测试。

server/tests/test_budget_endpoints.py

@@ -12,7 +12,7 @@ from sqlalchemy.pool import StaticPool
 from app.api.deps import get_db
 from app.db.base import Base
 from app.main import create_app
-from app.models.budget import BudgetAllocation
+from app.models.budget import BudgetAllocation, BudgetTransaction
 
 
 def build_session_factory() -> sessionmaker[Session]:
@@ -123,6 +123,90 @@ def test_admin_can_view_all_budget_allocations_without_is_admin_header() -> None
     payload = response.json()
     assert {item["department_name"] for item in payload["allocations"]} == {"市场部", "财务部"}
     assert {item["subject_code"] for item in payload["allocations"]} == {"travel", "office"}
+    assert payload["warnings"] == []
+    assert [item["period_key"] for item in payload["trend"]] == ["2026Q2"]
+    assert Decimal(payload["trend"][0]["total_amount"]) == Decimal("80000.00")
+
+
+def test_budget_summary_returns_real_trend_and_warnings() -> None:
+    client, session_factory = build_client()
+    now = datetime.now(UTC)
+    with session_factory() as db:
+        seed_budget_allocations(db)
+        db.add(
+            BudgetAllocation(
+                id="budget-market-travel-q1",
+                budget_no="BUD-MARKET-TRAVEL-Q1",
+                fiscal_year=2026,
+                period_type="quarter",
+                period_key="2026Q1",
+                department_id="dept-market",
+                department_name="市场部",
+                cost_center="CC-4100",
+                project_code=None,
+                subject_code="travel",
+                subject_name="差旅费",
+                original_amount=Decimal("40000.00"),
+                adjusted_amount=Decimal("0.00"),
+                status="active",
+                warning_threshold=Decimal("80.00"),
+                control_action="block",
+                created_at=now,
+                updated_at=now,
+            )
+        )
+        db.add_all(
+            [
+                BudgetTransaction(
+                    transaction_no="BTX-MARKET-TRAVEL-Q1",
+                    allocation_id="budget-market-travel-q1",
+                    source_type="claim",
+                    source_id="claim-q1",
+                    source_no="CLM-Q1",
+                    transaction_type="consume",
+                    amount=Decimal("12000.00"),
+                    before_available_amount=Decimal("40000.00"),
+                    after_available_amount=Decimal("28000.00"),
+                    operator="tester",
+                    reason="Q1 真实发生额",
+                    created_at=now,
+                ),
+                BudgetTransaction(
+                    transaction_no="BTX-MARKET-TRAVEL-Q2",
+                    allocation_id="budget-market-travel",
+                    source_type="claim",
+                    source_id="claim-q2",
+                    source_no="CLM-Q2",
+                    transaction_type="consume",
+                    amount=Decimal("41000.00"),
+                    before_available_amount=Decimal("50000.00"),
+                    after_available_amount=Decimal("9000.00"),
+                    operator="tester",
+                    reason="Q2 真实发生额",
+                    created_at=now,
+                ),
+            ]
+        )
+        db.commit()
+
+    response = client.get(
+        "/api/v1/budgets/summary?year=2026&period=2026Q2&cost_center=CC-4100",
+        headers={"x-auth-username": "admin", "x-auth-role-codes": "manager"},
+    )
+
+    assert response.status_code == 200
+    payload = response.json()
+    assert [item["subject_code"] for item in payload["allocations"]] == ["travel"]
+    assert [item["period_key"] for item in payload["trend"]] == ["2026Q1", "2026Q2"]
+    assert Decimal(payload["trend"][0]["used_amount"]) == Decimal("12000.00")
+    assert Decimal(payload["trend"][1]["used_amount"]) == Decimal("41000.00")
+    assert payload["warning_count"] == 1
+    assert payload["over_budget_count"] == 0
+    assert len(payload["warnings"]) == 1
+    warning = payload["warnings"][0]
+    assert warning["subject_code"] == "travel"
+    assert warning["severity"] == "warn"
+    assert Decimal(warning["usage_rate"]) == Decimal("82.00")
 
 
 def test_budget_monitor_is_limited_to_own_department_scope() -> None: