feat(flow): 新增分组执行与异步模式支持

refactor(executors): 将 Rhai 引擎评估逻辑迁移至 script_rhai 模块
docs: 添加 Flow 架构文档与示例 JSON
feat(i18n): 新增前端多语言支持
perf(axios): 优化 token 刷新与 401 处理逻辑
style: 统一代码格式化与简化条件判断

backend/src/flow/dsl.rs

@@ -88,6 +88,7 @@ impl From<FlowDSL> for super::domain::ChainDef {
                     condition: e.condition,
                 })
                 .collect(),
+            groups: std::collections::HashMap::default(),
         }
     }
 }
@@ -179,13 +180,43 @@ fn build_chain_from_design(design: &DesignSyntax) -> anyhow::Result<super::domai
     use super::domain::{ChainDef, NodeDef, NodeId, NodeKind, LinkDef};
 
     let mut nodes: Vec<NodeDef> = Vec::new();
+    let mut groups: std::collections::HashMap<String, super::domain::GroupDef> = std::collections::HashMap::new();
     for n in &design.nodes {
         let kind = match n.kind.as_str() {
             "start" => NodeKind::Start,
             "end" => NodeKind::End,
             "condition" => NodeKind::Condition,
+            "group" => NodeKind::Task, // group 本身不作为可执行节点，稍后跳过入 nodes
             _ => NodeKind::Task,
         };
+        if n.kind.as_str() == "group" {
+            // 解析分组：data.blockIDs（成员节点）、data.parentID（上层分组）、data.awaitPolicy（等待策略）
+            let members: Vec<String> = n
+                .data
+                .get("blockIDs")
+                .and_then(|v| v.as_array())
+                .map(|arr| arr.iter().filter_map(|x| x.as_str().map(|s| s.to_string())).collect())
+                .unwrap_or_default();
+            let parent_id: Option<String> = n
+                .data
+                .get("parentID")
+                .and_then(|v| v.as_str())
+                .map(|s| s.to_string());
+            let await_policy = match n
+                .data
+                .get("awaitPolicy")
+                .and_then(|v| v.as_str())
+                .unwrap_or("branch_exit")
+            {
+                "none" => super::domain::GroupAwaitPolicy::None,
+                "node_leave" => super::domain::GroupAwaitPolicy::NodeLeave,
+                "flow_end" => super::domain::GroupAwaitPolicy::FlowEnd,
+                _ => super::domain::GroupAwaitPolicy::BranchExit,
+            };
+            groups.insert(n.id.clone(), super::domain::GroupDef { id: n.id.clone(), parent_id, members, await_policy });
+            // group 节点不加入执行节点集合
+            continue;
+        }
         // 从节点 data.title 读取名称，若不存在则为空字符串
         let name = n.data.get("title").and_then(|v| v.as_str()).unwrap_or("").to_string();
         // 将可执行类型映射到任务标识（用于绑定任务实现）
@@ -268,7 +299,7 @@ fn build_chain_from_design(design: &DesignSyntax) -> anyhow::Result<super::domai
         links.push(LinkDef { from: NodeId(e.from.clone()), to: NodeId(e.to.clone()), condition: cond });
     }
 
-    Ok(ChainDef { name: design.name.clone(), nodes, links })
+    Ok(ChainDef { name: design.name.clone(), nodes, links, groups })
 }
 
 // Rewire external API to typed syntax -> validate -> build