fix: Further refine Mermaid diagram syntax in README.md

This commit applies additional fixes to the Mermaid diagram in README.md
by introducing explicit subgraph IDs (e.g., subgraph ext_layer[...])
and standardizing parentheses in node labels (e.g., (外部接入预留) to (外部接入预留)).
These changes enhance the diagram's robustness and ensure consistent rendering.

README.md

@@ -204,7 +204,7 @@ graph TB
   classDef control stroke-dasharray: 3 3,stroke:#8e24aa,stroke-width:1.6px;
   classDef async stroke-dasharray: 2 4,stroke:#2e7d32,stroke-width:1.6px;
 
-  subgraph 外部系统与数据源层
+  subgraph ext_layer[外部系统与数据源层]
     ext_contrib[社区贡献者]
     ext_sheet[Google表格 / 外部表格数据]
     ext_md[外部 Markdown 提示词]
@@ -214,7 +214,7 @@ graph TB
     ext_api -.-> ext_sheet
   end
 
-  subgraph 数据接入与采集层
+  subgraph ingest_layer[数据接入与采集层]
     excel_raw[prompt_excel/*.xlsx 原始表]
     md_raw[prompt_docs/外部MD输入]
     excel_to_docs[prompts-library/scripts/excel_to_docs.py]
@@ -228,7 +228,7 @@ graph TB
     docs_to_excel --> ingest_bus
   end
 
-  subgraph 数据处理与智能决策层（核心）
+  subgraph core_layer[数据处理与智能决策层 / 核心]
     validate[字段校验与规范化] --> transform[格式映射转换引擎]
     transform --> artifacts_md[生成 prompt_docs/规范MD]
     transform --> artifacts_xlsx[生成 prompt_excel/导出XLSX]
@@ -237,7 +237,7 @@ graph TB
     ingest_bus --> validate
   end
 
-  subgraph 执行与消费层
+  subgraph consume_layer[执行与消费层]
     artifacts_md --> catalog_coding[prompts/coding_prompts 编程链路提示词]
     artifacts_md --> catalog_system[prompts/system_prompts 行为约束提示词]
     artifacts_md --> catalog_assist[prompts/assistant_prompts 辅助提示词]
@@ -248,18 +248,18 @@ graph TB
     ai_flow --> deliverables[项目上下文 / 计划 / 代码产出]
   end
 
-  subgraph 用户交互与接口层
+  subgraph ux_layer[用户交互与接口层]
     cli[CLI: python main.py] --> orchestrator
     makefile[Makefile 任务封装] -.-> cli
     readme[README.md 使用指南] -.-> cli
   end
 
-  subgraph 基础设施与横切能力层
+  subgraph infra_layer[基础设施与横切能力层]
     git[Git 版本控制] -.-> orchestrator
     backups[backups/一键备份.sh · backups/快速备份.py] -.-> artifacts_md
     deps[requirements.txt · scripts/requirements.txt 依赖] -.-> orchestrator
     config[prompts-library/scripts/config.yaml 配置] -.-> orchestrator
-    monitor[日志/监控（外部接入预留）] -.-> orchestrator
+    monitor[日志/监控 (外部接入预留)] -.-> orchestrator
   end
 
   %% 横切覆盖示意