Add automated fix workflow for AI nutritionist page

- Create .fixes/ directory structure for tracking repairs
- Add FIX-001 to FIX-009 repair tasks based on Cursor review
- Add automation scripts (start-fix.sh, complete-fix.sh)
- Update HEARTBEAT.md with repair checklist
- Create AUTOMATION_PLAN.md with workflow documentation

Fixes address:
- Remove fake initial data
- Add clear chat button
- Split oversized component
- Optimize multi-image upload
- Fix scroll behavior
- Remove dead code
- Extract hardcoded config

msh_single_uniapp/.fixes/backlog/FIX-007-remove-dead-code.md

@@ -0,0 +1,12 @@
+# FIX-007: 删除废弃方法
+
+**状态**: 待开始  
+**创建时间**: 2026-02-28  
+**优先级**: 低  
+**负责人**: msh-agent  
+
+---
+
+## 问题描述
+
+`sendImageMessage` 方法注释"已废弃，逻辑合并到 sendMessage"，建议删除该方法，避免误导。