The AddTrailingSlash() Pre middleware was redirecting requests like
/api/admin/users to /api/admin/users/, but admin routes were registered
without trailing slashes, causing routes to not match (404/401 errors).
Mobile API routes already have trailing slashes explicitly defined,
so this middleware was unnecessary and caused conflicts.
Also fix APNS_AUTH_KEY_PATH to use environment variable.
🤖 Generated with [Claude Code](https://claude.com/claude-code)
Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>