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/src/app/services/budget.py

@@ -92,6 +92,7 @@ class BudgetService(BudgetSupportMixin):
         over_budget_count = sum(
             1 for item in allocations if item.balance.available_amount < Decimal("0.00")
         )
+        warnings = self.build_summary_warnings(allocations)
         return BudgetSummaryRead(
             fiscal_year=fiscal_year,
             period_key=period_key,
@@ -102,6 +103,13 @@ class BudgetService(BudgetSupportMixin):
             warning_count=warning_count,
             over_budget_count=over_budget_count,
             allocations=allocations,
+            trend=self.build_summary_trend(
+                fiscal_year=fiscal_year,
+                department_id=department_id,
+                department_name=department_name,
+                cost_center=cost_center,
+            ),
+            warnings=warnings,
         )
 
     def create_or_update_allocation(

server/src/app/services/budget_support.py

@@ -10,7 +10,12 @@ from sqlalchemy import select
 from app.models.budget import BudgetAllocation, BudgetReservation, BudgetTransaction
 from app.models.financial_record import ExpenseClaim
 from app.models.organization import OrganizationUnit
-from app.schemas.budget import BudgetAllocationRead, BudgetTransactionRead
+from app.schemas.budget import (
+    BudgetAllocationRead,
+    BudgetTransactionRead,
+    BudgetTrendPointRead,
+    BudgetWarningRead,
+)
 from app.services.budget_types import (
     BUDGET_SUBJECT_LABELS,
     BudgetBalance,
@@ -89,6 +94,120 @@ class BudgetSupportMixin:
         ).all()
         return [BudgetTransactionRead.model_validate(row) for row in rows]
 
+    def build_summary_trend(
+        self,
+        *,
+        fiscal_year: int | None = None,
+        department_id: str | None = None,
+        department_name: str | None = None,
+        cost_center: str | None = None,
+    ) -> list[BudgetTrendPointRead]:
+        stmt = (
+            select(BudgetAllocation)
+            .where(BudgetAllocation.subject_code.in_(SUPPORTED_BUDGET_SUBJECT_CODES))
+            .order_by(
+                BudgetAllocation.fiscal_year.asc(),
+                BudgetAllocation.period_key.asc(),
+            )
+        )
+        if fiscal_year is not None:
+            stmt = stmt.where(BudgetAllocation.fiscal_year == fiscal_year)
+        if department_id:
+            stmt = stmt.where(BudgetAllocation.department_id == department_id)
+        if department_name:
+            stmt = stmt.where(BudgetAllocation.department_name == department_name)
+        if cost_center:
+            stmt = stmt.where(BudgetAllocation.cost_center == cost_center)
+
+        buckets: dict[str, dict[str, Decimal]] = {}
+        for allocation in self.db.scalars(stmt).all():
+            balance = self.get_balance(allocation)
+            bucket = buckets.setdefault(
+                allocation.period_key,
+                {
+                    "total_amount": Decimal("0.00"),
+                    "reserved_amount": Decimal("0.00"),
+                    "consumed_amount": Decimal("0.00"),
+                    "available_amount": Decimal("0.00"),
+                },
+            )
+            bucket["total_amount"] += balance.total_amount
+            bucket["reserved_amount"] += balance.reserved_amount
+            bucket["consumed_amount"] += balance.consumed_amount
+            bucket["available_amount"] += balance.available_amount
+
+        trend: list[BudgetTrendPointRead] = []
+        for period_key in sorted(buckets, key=self._period_sort_key):
+            bucket = buckets[period_key]
+            used_amount = bucket["reserved_amount"] + bucket["consumed_amount"]
+            usage_rate = Decimal("0.00")
+            if bucket["total_amount"] > Decimal("0.00"):
+                usage_rate = (
+                    (used_amount / bucket["total_amount"]) * Decimal("100")
+                ).quantize(Decimal("0.01"))
+            trend.append(
+                BudgetTrendPointRead(
+                    period_key=period_key,
+                    label=self._period_label(period_key),
+                    total_amount=self._money(bucket["total_amount"]),
+                    reserved_amount=self._money(bucket["reserved_amount"]),
+                    consumed_amount=self._money(bucket["consumed_amount"]),
+                    used_amount=self._money(used_amount),
+                    available_amount=self._money(bucket["available_amount"]),
+                    usage_rate=usage_rate,
+                )
+            )
+        return trend
+
+    def build_summary_warnings(self, allocations: list[BudgetAllocationRead]) -> list[BudgetWarningRead]:
+        warnings: list[BudgetWarningRead] = []
+        for allocation in allocations:
+            balance = allocation.balance
+            if balance.available_amount < Decimal("0.00"):
+                severity = "danger"
+                message = (
+                    f"{allocation.department_name} {allocation.subject_name} 可用预算为 "
+                    f"{balance.available_amount} 元，已超出预算。"
+                )
+            elif balance.usage_rate >= allocation.warning_threshold:
+                severity = "warn"
+                message = (
+                    f"{allocation.department_name} {allocation.subject_name} 使用率已达 "
+                    f"{balance.usage_rate}%，达到预警线 {allocation.warning_threshold}%。"
+                )
+            else:
+                continue
+            warnings.append(
+                BudgetWarningRead(
+                    allocation_id=allocation.id,
+                    budget_no=allocation.budget_no,
+                    fiscal_year=allocation.fiscal_year,
+                    period_key=allocation.period_key,
+                    department_name=allocation.department_name,
+                    cost_center=allocation.cost_center,
+                    subject_code=allocation.subject_code,
+                    subject_name=allocation.subject_name,
+                    total_amount=balance.total_amount,
+                    reserved_amount=balance.reserved_amount,
+                    consumed_amount=balance.consumed_amount,
+                    available_amount=balance.available_amount,
+                    usage_rate=balance.usage_rate,
+                    warning_threshold=allocation.warning_threshold,
+                    severity=severity,
+                    message=message,
+                    occurred_at=allocation.updated_at,
+                )
+            )
+        return sorted(
+            warnings,
+            key=lambda item: (
+                0 if item.severity == "danger" else 1,
+                -float(item.usage_rate),
+                item.department_name,
+                item.subject_name,
+            ),
+        )
+
     def get_allocation_row(self, allocation_id: str) -> BudgetAllocation | None:
         self.ensure_budget_ready()
         return self.db.get(BudgetAllocation, allocation_id)
@@ -543,6 +662,20 @@ class BudgetSupportMixin:
         quarter = ((max(1, min(month, 12)) - 1) // 3) + 1
         return f"{year}Q{quarter}"
 
+    @staticmethod
+    def _period_label(period_key: str) -> str:
+        text = str(period_key or "").strip().upper()
+        if len(text) >= 6 and text[:4].isdigit() and text[4] == "Q":
+            return f"{text[:4]}年{text[4:]}"
+        return text or "未分期"
+
+    @staticmethod
+    def _period_sort_key(period_key: str) -> tuple[int, int, str]:
+        text = str(period_key or "").strip().upper()
+        year = int(text[:4]) if len(text) >= 4 and text[:4].isdigit() else 0
+        quarter = int(text[5:]) if len(text) >= 6 and text[4] == "Q" and text[5:].isdigit() else 0
+        return year, quarter, text
+
     def _period_from_claim(self, claim: ExpenseClaim) -> tuple[int, str]:
         occurred_at = claim.occurred_at or claim.submitted_at or datetime.now(UTC)
         return occurred_at.year, self._quarter_key(occurred_at.year, occurred_at.month)