refactor: region from document, not app config

- Add region column to leaudit_documents + LeauditDocument model
- AuditServiceImpl: read region from document.region, not APP_REGION
- RuleServiceImpl: ListBindings/CreateBinding accept Region parameter
- RuleBindingCreateDTO: add region field
- RuleController: pass region from query param/DTO to service
- APP_REGION removed from binding queries; region flows from document

Region is now per-document: each document carries its region at upload
time, and rules are matched to the document's region at run time.

fastapi_modules/fastapi_leaudit/domian/Dto/ruleBindingDto.py

@@ -9,6 +9,7 @@ class RuleBindingCreateDTO(BaseModel):
     docTypeId: int = Field(..., description="文档类型ID → leaudit_document_types.id")
     docTypeCode: str | None = Field(None, description="文档类型编码（冗余快速匹配）")
     ruleSetId: int = Field(..., description="规则集ID → leaudit_rule_sets.id")
+    region: str = Field("default", description="适用地区")
     bindingMode: str = Field("explicit", description="绑定模式: explicit / wildcard / fallback")
     priority: int = Field(0, description="优先级（数值越大优先级越高）")
     note: str | None = Field(None, description="备注说明")