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

pyproject.toml

@@ -6,6 +6,7 @@ requires-python = ">=3.12"
 dependencies = [
     "ag-ui-protocol==0.1.13",
     "agentscope>=1.0.18",
+    "aiosmtplib>=5.1.0",
     "alembic==1.18.4",
     "asyncpg==0.30.0",
     "cryptography==46.0.3",
@@ -13,6 +14,8 @@ dependencies = [
     "email-validator==2.3.0",
     "fastapi==0.135.1",
     "lunar-python>=1.4.8",
+    "openpyxl>=3.1.5",
+    "pillow>=12.2.0",
     "pydantic==2.12.5",
     "pydantic-settings==2.13.1",
     "pyjwt==2.11.0",