feat: 新增预算后端服务与差旅风险规则库

后端新增预算模型、端点和服务模块，支持预算 CRUD 和余额
查询，清理旧生成规则文件并替换为按严重等级分类的差旅风
险规则库，优化认证权限和报销单访问策略，新增财务规则目
录和演示数据构建脚本，前端预算中心增加对话框交互，完善
审计页面运行时模型和元数据展示，补充单元测试。

server/rules/risk-rules/risk.travel.low.attachment_ocr_missing.json

@@ -0,0 +1,109 @@
+{
+  "schema_version": "2.0",
+  "rule_code": "risk.travel.low.attachment_ocr_missing",
+  "name": "差旅附件无法识别低风险",
+  "description": "差旅报销已上传附件但没有可读取的 OCR 文本或关键票据信息，提醒人工补录或重新上传。",
+  "enabled": true,
+  "requires_attachment": true,
+  "risk_dimension": "travel_reimbursement_control",
+  "risk_category": "差旅费-附件质量",
+  "ontology_signal": "travel_attachment_ocr_missing",
+  "evaluator": "template_rule",
+  "finance_rule_code": "rule.expense.company_travel_expense_reimbursement",
+  "finance_rule_sheet": "公司差旅费报销规则",
+  "business_stage": [
+    "expense_application",
+    "reimbursement"
+  ],
+  "expense_types": [
+    "travel"
+  ],
+  "applies_to": {
+    "domains": [
+      "expense",
+      "travel"
+    ],
+    "expense_types": [
+      "travel"
+    ],
+    "business_stages": [
+      "expense_application",
+      "reimbursement"
+    ]
+  },
+  "inputs": {
+    "fields": [
+      {
+        "key": "attachment.ocr_text",
+        "label": "票据 OCR 全文",
+        "type": "text",
+        "source": "attachment"
+      }
+    ]
+  },
+  "params": {
+    "field_keys": [
+      "attachment.ocr_text"
+    ],
+    "required_fields": [
+      "attachment.ocr_text"
+    ],
+    "condition_summary": "差旅附件缺少可读取 OCR 文本。",
+    "message_template": "差旅附件暂未识别到有效票据信息，请重新上传清晰附件或人工补录。",
+    "template_key": "field_required_v1"
+  },
+  "outcomes": {
+    "pass": {
+      "severity": "none",
+      "action": "continue"
+    },
+    "fail": {
+      "severity": "low",
+      "action": "warning",
+      "risk_score": 38
+    }
+  },
+  "metadata": {
+    "owner": "admin",
+    "stability": "admin_configured",
+    "source_ref": "差旅费报销风险规则库 / admin 手工配置",
+    "created_at": "2026-05-26T07:06:27.746703+00:00",
+    "created_by": "admin",
+    "risk_score": 38,
+    "risk_level": "low",
+    "rule_title": "差旅附件无法识别低风险",
+    "finance_rule_code": "rule.expense.company_travel_expense_reimbursement",
+    "finance_rule_sheet": "公司差旅费报销规则",
+    "business_stage": [
+      "expense_application",
+      "reimbursement"
+    ],
+    "expense_types": [
+      "travel"
+    ],
+    "implementation_note": "使用当前规则中心 JSON 风险规则执行器可识别的字段与模板配置。",
+    "risk_level_label": "低风险",
+    "risk_score_model": "risk_score_v3",
+    "risk_score_detail": {
+      "score": 38,
+      "level": "low",
+      "level_label": "低风险",
+      "model": "risk_score_v3",
+      "source": "admin_manual_travel_risk_catalog",
+      "reason": "按差旅费报销高/中/低风险分层手工设定。"
+    }
+  },
+  "severity": "low",
+  "risk_score": 38,
+  "risk_level": "low",
+  "template_key": "field_required_v1",
+  "risk_level_label": "低风险",
+  "risk_score_detail": {
+    "score": 38,
+    "level": "low",
+    "level_label": "低风险",
+    "model": "risk_score_v3",
+    "source": "admin_manual_travel_risk_catalog",
+    "reason": "按差旅费报销高/中/低风险分层手工设定。"
+  }
+}