feat(core): add audit logging to all mutation operations

Create audit_log SeaORM entity and audit_service::record() helper.
Integrate audit recording into 35 mutation endpoints across all modules:
- erp-auth: user/role/organization/department/position CRUD (15 actions)
- erp-config: dictionary/menu/setting/numbering_rule CRUD (15 actions)
- erp-workflow: definition/instance/task operations (8 actions)
- erp-message: send/system/mark_read/delete (5 actions)

Uses fire-and-forget pattern — audit failures logged but non-blocking.

crates/erp-workflow/src/service/definition_service.rs

@@ -10,6 +10,8 @@ use crate::dto::{
 use crate::engine::parser;
 use crate::entity::process_definition;
 use crate::error::{WorkflowError, WorkflowResult};
+use erp_core::audit::AuditLog;
+use erp_core::audit_service;
 use erp_core::error::check_version;
 use erp_core::events::EventBus;
 use erp_core::types::Pagination;
@@ -107,6 +109,13 @@ impl DefinitionService {
             serde_json::json!({ "definition_id": id, "key": req.key }),
         ));
 
+        audit_service::record(
+            AuditLog::new(tenant_id, Some(operator_id), "process_definition.create", "process_definition")
+                .with_resource_id(id),
+            db,
+        )
+        .await;
+
         Ok(ProcessDefinitionResp {
             id,
             name: req.name.clone(),
@@ -182,6 +191,13 @@ impl DefinitionService {
             .await
             .map_err(|e| WorkflowError::Validation(e.to_string()))?;
 
+        audit_service::record(
+            AuditLog::new(tenant_id, Some(operator_id), "process_definition.update", "process_definition")
+                .with_resource_id(id),
+            db,
+        )
+        .await;
+
         Ok(Self::model_to_resp(&updated))
     }
 
@@ -231,6 +247,13 @@ impl DefinitionService {
             serde_json::json!({ "definition_id": id }),
         ));
 
+        audit_service::record(
+            AuditLog::new(tenant_id, Some(operator_id), "process_definition.publish", "process_definition")
+                .with_resource_id(id),
+            db,
+        )
+        .await;
+
         Ok(Self::model_to_resp(&updated))
     }
 
@@ -259,6 +282,13 @@ impl DefinitionService {
             .await
             .map_err(|e| WorkflowError::Validation(e.to_string()))?;
 
+        audit_service::record(
+            AuditLog::new(tenant_id, Some(operator_id), "process_definition.delete", "process_definition")
+                .with_resource_id(id),
+            db,
+        )
+        .await;
+
         Ok(())
     }