docs: reorganize documentation structure and add analysis guidelines

- Move existing documentation files to reference_docs/ directory
- Add documentation guidelines section to CLAUDE.md
- Add clsBOMManager LoadData flow analysis with Mermaid diagrams

Co-Authored-By: Claude Sonnet 4.5 <noreply@anthropic.com>

CLAUDE.md

@@ -130,6 +130,18 @@ Run tests from the VBA editor or Excel macros:
 - `布莱迪公司压力表产品选型大表.md` - Complete product model numbering system (716 lines, Chinese)
 - `VBA/clsBOMManager使用说明.md` - API documentation and usage examples for clsBOMManager (546 lines, Chinese)
 
+### Documentation Guidelines
+
+**Analysis Documents**
+- When analyzing VBA code, modules, or methods (e.g., creating flow diagrams, architecture explanations), save all generated analysis documents to the `reference_docs/` directory
+- Use descriptive filenames that clearly indicate the content (e.g., `clsBOMManager_LoadData流程分析.md`)
+- Prefer using Mermaid diagrams for visualizing:
+  - Flowcharts (method execution flow)
+  - Sequence diagrams (interactions between objects)
+  - Class diagrams (relationships between classes)
+  - State diagrams (state transitions)
+- Keep analysis documents in Chinese when the original code comments are in Chinese
+
 ## Module Registry
 
 `VBA/vba_metadata.json` maps VBA module names to their file locations in the repository. Update this file when: