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。

web/src/assets/styles/views/budget-center-dialog.css

@@ -290,20 +290,20 @@
 }
 
 .budget-edit-foot {
-  padding: 18px 24px 20px;
+  padding: 14px 24px 16px;
   display: flex;
   align-items: center;
-  justify-content: center;
-  gap: 18px;
+  justify-content: flex-end;
+  gap: 10px;
   border-top: 1px solid #edf1f6;
   background: #fff;
 }
 
 .budget-edit-foot button {
-  height: 40px;
-  min-width: 156px;
-  border-radius: 7px;
-  font-size: 14px;
+  height: 36px;
+  min-width: 96px;
+  border-radius: 8px;
+  font-size: 13px;
   font-weight: 800;
   cursor: pointer;
 }
@@ -372,3 +372,141 @@
     width: 100%;
   }
 }
+
+@media (max-width: 1366px), (max-height: 820px) {
+  .budget-dialog-backdrop {
+    padding: 14px;
+  }
+
+  .budget-edit-dialog {
+    width: min(920px, calc(100vw - 28px));
+    max-height: calc(100vh - 28px);
+  }
+
+  .budget-edit-head {
+    min-height: 48px;
+    padding: 0 18px;
+  }
+
+  .budget-edit-head strong {
+    font-size: 16px;
+  }
+
+  .budget-dialog-close {
+    width: 28px;
+    height: 28px;
+    font-size: 18px;
+  }
+
+  .budget-edit-body {
+    padding: 12px 18px 10px;
+  }
+
+  .budget-edit-section + .budget-edit-section {
+    margin-top: 10px;
+  }
+
+  .budget-edit-section h3 {
+    margin-bottom: 8px;
+    font-size: 14px;
+  }
+
+  .budget-edit-form-grid {
+    gap: 10px 16px;
+  }
+
+  .budget-edit-form-grid label,
+  .budget-edit-textarea {
+    gap: 5px;
+    font-size: 12px;
+  }
+
+  .budget-edit-form-grid select {
+    height: 34px;
+  }
+
+  .budget-edit-textarea {
+    margin-top: 8px;
+  }
+
+  .budget-edit-textarea textarea {
+    min-height: 58px;
+    padding: 8px 12px 20px;
+    line-height: 1.45;
+  }
+
+  .budget-edit-table th,
+  .budget-edit-table td {
+    height: 40px;
+    padding: 6px 8px;
+  }
+
+  .budget-edit-table input,
+  .budget-edit-table select {
+    height: 30px;
+    padding: 0 8px;
+  }
+
+  .budget-row-delete {
+    width: 28px;
+    height: 28px;
+    font-size: 16px;
+  }
+
+  .budget-add-row-btn {
+    height: 26px;
+    margin-top: 6px;
+    font-size: 12px;
+  }
+
+  .budget-edit-total {
+    height: 34px;
+    margin-top: 6px;
+  }
+
+  .budget-edit-total span,
+  .budget-edit-foot button {
+    font-size: 13px;
+  }
+
+  .budget-edit-total strong {
+    font-size: 15px;
+  }
+
+  .budget-edit-foot {
+    padding: 10px 18px 12px;
+    gap: 8px;
+  }
+
+  .budget-edit-foot button {
+    height: 32px;
+    min-width: 88px;
+  }
+}
+
+@media (max-height: 700px) {
+  .budget-dialog-backdrop {
+    padding: 8px;
+  }
+
+  .budget-edit-dialog {
+    max-height: calc(100vh - 16px);
+  }
+
+  .budget-edit-body {
+    padding: 10px 16px 8px;
+  }
+
+  .budget-edit-textarea textarea {
+    min-height: 46px;
+  }
+
+  .budget-edit-table th,
+  .budget-edit-table td {
+    height: 36px;
+  }
+
+  .budget-edit-foot {
+    padding: 8px 16px;
+  }
+}

web/src/assets/styles/views/budget-center-view.css

@@ -546,14 +546,19 @@
 }
 
 .legend-line {
-  width: 18px;
-  height: 0;
-  border-top: 2px dashed #2f7fd7;
+  width: 10px;
+  height: 10px;
+  border-radius: 3px;
+  background: #13a66b;
 }
 
-.legend-line.used {
-  border-top-style: solid;
-  border-top-color: #13a66b;
+.legend-line.occupied {
+  background: #f59e0b;
+}
+
+.legend-line.available {
+  background: #e5edf3;
+  border: 1px solid #cbd5e1;
 }
 
 .budget-chart-panel {
@@ -569,6 +574,41 @@
   padding: 12px 20px 18px;
 }
 
+.budget-alert-empty {
+  min-height: 220px;
+  padding: 28px 24px 30px;
+  display: grid;
+  place-items: center;
+  align-content: center;
+  gap: 10px;
+  text-align: center;
+}
+
+.budget-alert-empty-icon {
+  width: 44px;
+  height: 44px;
+  border-radius: 12px;
+  display: grid;
+  place-items: center;
+  background: #e9f7f1;
+  color: #059669;
+  font-size: 24px;
+}
+
+.budget-alert-empty strong {
+  color: #111827;
+  font-size: 16px;
+  font-weight: 800;
+}
+
+.budget-alert-empty p {
+  max-width: 260px;
+  margin: 0;
+  color: #64748b;
+  font-size: 13px;
+  line-height: 1.6;
+}
+
 .budget-alert-row {
   min-height: 46px;
   display: grid;