feat(flows): 新增流程编辑器基础功能与相关组件

feat(backend): 添加流程模型与服务支持
feat(frontend): 实现流程编辑器UI与交互
feat(assets): 添加流程节点图标资源
feat(plugins): 实现上下文菜单和运行时插件
feat(components): 新增基础节点和侧边栏组件
feat(routes): 添加流程相关路由配置
feat(models): 创建流程和运行日志数据模型
feat(services): 实现流程服务层逻辑
feat(migration): 添加流程相关数据库迁移
feat(config): 更新前端配置支持流程编辑器
feat(utils): 增强axios错误处理和工具函数

backend/migration/src/m20220101_000014_create_flows.rs

@@ -0,0 +1,40 @@
+use sea_orm_migration::prelude::*;
+
+#[derive(DeriveMigrationName)]
+pub struct Migration;
+
+#[async_trait::async_trait]
+impl MigrationTrait for Migration {
+    async fn up(&self, manager: &SchemaManager) -> Result<(), DbErr> {
+        manager
+            .create_table(
+                Table::create()
+                    .table(Flows::Table)
+                    .if_not_exists()
+                    .col(ColumnDef::new(Flows::Id).string_len(64).not_null().primary_key())
+                    .col(ColumnDef::new(Flows::Name).string().null())
+                    .col(ColumnDef::new(Flows::Yaml).text().null())
+                    .col(ColumnDef::new(Flows::DesignJson).text().null())
+                    .col(ColumnDef::new(Flows::CreatedAt).timestamp().not_null().default(Expr::current_timestamp()))
+                    .col(ColumnDef::new(Flows::UpdatedAt).timestamp().not_null().default(Expr::current_timestamp()))
+                    .to_owned()
+            )
+            .await?;
+        Ok(())
+    }
+
+    async fn down(&self, manager: &SchemaManager) -> Result<(), DbErr> {
+        manager.drop_table(Table::drop().table(Flows::Table).to_owned()).await
+    }
+}
+
+#[derive(Iden)]
+enum Flows {
+    Table,
+    Id,
+    Name,
+    Yaml,
+    DesignJson,
+    CreatedAt,
+    UpdatedAt,
+}