fix: Display timestamps in user's local timezone in installation scripts

- Convert UTC timestamps to local timezone in install-remote.ps1
- Convert UTC timestamps to local timezone in install-remote.sh
- Support cross-platform date conversion (GNU date and BSD date)
- Remove 'UTC' suffix from timestamp displays

🤖 Generated with [Claude Code](https://claude.com/claude-code)

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

.claude/prompt-templates/plan.md

@@ -1,10 +1,3 @@
----
-name: plan
-description: 软件架构规划和技术实现计划分析模板
-category: planning
-keywords: [规划, 架构, 实现计划, 技术设计, 修改方案]
----
-
 # 软件架构规划模板
 # AI Persona & Core Mission