feat: add avatar upload support (MinIO bucket, PocketBase field, SvelteKit API, iOS ProfileView)

scraper/internal/storage/pocketbase.go

@@ -458,6 +458,8 @@ type migration struct {
 var migrations = []migration{
 	// user_id was added to progress after initial deploy.
 	{"progress", "user_id", "text"},
+	// avatar_url stores the MinIO presign path for the user's profile picture.
+	{"app_users", "avatar_url", "text"},
 }
 
 // EnsureMigrations idempotently adds any fields that are missing from existing