* 🐛 fix(email): use || instead of ?? to handle empty string from Dockerfile
Dockerfile sets empty string defaults for email env vars (SMTP_FROM,
SMTP_HOST, etc). The ?? operator doesn't treat empty strings as nullish,
causing email sending to fail with "Mail Account:" being empty.
Fixes#11757
* ✨ feat(workflow): add Claude migration support workflow
Add automated support for migration feedback issues (#11757, #11707):
- Auto-respond to new comments on migration issues
- Check for sensitive information leaks and warn users
- Read latest docs before responding
- Validate required information from issue description
- Match issues against documented FAQ solutions
* 🐛 fix(auth): add APP_URL trailing slash check
Detect and warn when APP_URL ends with a trailing slash, which causes
double slashes in redirect URLs (e.g., https://example.com//).
* ✨ feat(workflow): add Claude migration support workflow
Add automated support for migration feedback issues (#11757, #11707):
- Auto-respond to new comments on migration issues
- Check for sensitive information leaks and warn users
- Read latest docs before responding
- Validate required information from issue description
- Match issues against documented FAQ solutions
- Minimize resolved/success feedback comments
* 📝 docs: add browser cache clearing guide and improve migration workflow
- Add troubleshooting section for clearing browser site data after migration
- Exclude maintainers (tjx666, arvinxx) from auto-reply workflow
- Add references to auth.mdx and checkDeprecatedAuth.js in workflow
* 📝 docs: add migration internals technical documentation
- Explain users table vs accounts table relationship
- Document simple vs full migration principles
- Add troubleshooting guide with SQL examples
- Link from migration guides to new doc
