Add resolveAvatarUrl(userId, storedValue) helper that tries MinIO first,
then falls back to the stored HTTP URL for OAuth users (Google/GitHub)
who have never uploaded a custom avatar.
Add getUserById() to pocketbase helpers for batch avatar resolution in
comments. Update all 6 call sites to use the new helper.
- Go scraper: add PresignAvatarUploadURL/PresignAvatarURL/DeleteAvatar to
Store interface, implement on HybridStore+MinioClient, register
GET /api/presign/avatar-upload/{userId} and /api/presign/avatar/{userId}
- SvelteKit: replace direct AWS S3 SDK in minio.ts with presign calls to
the Go scraper; rewrite avatar +server.ts (POST=presign, PATCH=record key)
- iOS: rewrite uploadAvatar() as 3-step presigned PUT flow; refactor
chip components into shared ChipButton in CommonViews.swift
