feat(feedback): implement user feedback collection system with email reporting

Backend:
- Add user_feedback table with RLS policy
- Create feedback submission API (multipart/form-data)
- Implement xlsx report generation with embedded images
- Add scheduled email delivery via Feishu SMTP
- Create HTML email templates (daily_report, no_feedback)

Frontend:
- Add feedback screen with type selection and image picker
- Support anonymous submission via skipAuth flag
- Collect device info and app version

Protocol:
- Document feedback API contract and error codes
- Update http-error-codes.md with FEEDBACK_* codes

.env.example

@@ -57,8 +57,28 @@ ERYAO_STORAGE__AVATAR__BUCKET=avatars
 ERYAO_STORAGE__SIGNED_URL_TTL_SECONDS=600
 ERYAO_STORAGE__ATTACHMENT__MAX_SIZE_MB=20
 ERYAO_STORAGE__AVATAR__MAX_SIZE_MB=2
+ERYAO_STORAGE__FEEDBACK__BUCKET=feedback-images
+ERYAO_STORAGE__FEEDBACK__MAX_SIZE_MB=5
 ERYAO_STORAGE__RETENTION_DAYS=30
 
+############
+# Feedback Report
+############
+ERYAO_FEEDBACK_REPORT__EMAIL=support@example.com
+ERYAO_FEEDBACK_REPORT__CRON=0 10 * * *
+ERYAO_FEEDBACK_REPORT__ENABLED=false
+
+############
+# Email SMTP 配置（飞书企业邮箱）
+############
+ERYAO_EMAIL__HOST=smtp.feishu.cn
+ERYAO_EMAIL__PORT=465
+ERYAO_EMAIL__USERNAME=robot@xunmee.com
+ERYAO_EMAIL__PASSWORD=
+ERYAO_EMAIL__USE_SSL=true
+ERYAO_EMAIL__FROM_ADDRESS=robot@xunmee.com
+ERYAO_EMAIL__FROM_NAME=Eryao 反馈系统
+
 ############
 # LLM API KEY
 ############