feat(example): 添加人脸注册按钮和ID显示功能

- 添加注册按钮，点击生成随机人脸ID（格式：F + 8位数字）
- 实时显示检测到的人脸对应的ID
- 使用彩色标签区分已注册（绿色）和未注册（橙色）状态

Quick task: 260330-ld1

.planning/STATE.md

@@ -0,0 +1,27 @@
+# Project State
+
+**Project:** ArcSoft Face Recognition Plugin
+**Last activity:** 2026-03-30 - Initialized project
+
+## Current Phase
+
+**Phase:** 1 - Example App Enhancement
+**Status:** Ready to start
+**Started:** Not yet
+
+### Progress
+
+| Metric | Value |
+|--------|-------|
+| Requirements | 3 active |
+| Phases | 1 total |
+| Progress | 0% |
+
+### Quick Tasks Completed
+
+| # | Description | Date | Commit | Directory |
+|---|-------------|------|--------|-----------|
+| 260330-ld1 | 在example的人脸识别预览页面增加注册按钮和人脸ID显示 | 2026-03-30 | - | [260330-ld1-example-id-id](./quick/260330-ld1-example-id-id/) |
+
+---
+*State initialized: 2026-03-30*