refactor(server/api): migrate admin_smtp/admin_tracks + playlist refresh preludes (A2 6/N)

internal/api/playlists_discover_refresh.go

@@ -8,7 +8,6 @@ import (
 	"github.com/jackc/pgx/v5"
 
 	"git.fabledsword.com/bvandeusen/minstrel/internal/apierror"
-	"git.fabledsword.com/bvandeusen/minstrel/internal/auth"
 	"git.fabledsword.com/bvandeusen/minstrel/internal/db/dbq"
 	"git.fabledsword.com/bvandeusen/minstrel/internal/playlists"
 )
@@ -31,9 +30,8 @@ type discoverRefreshResp struct {
 // RequireUser middleware). Each user only ever refreshes their own
 // Discover — no admin route, no cross-user impersonation.
 func (h *handlers) handleDiscoverRefresh(w http.ResponseWriter, r *http.Request) {
-	user, ok := auth.UserFromContext(r.Context())
+	user, ok := requireUser(w, r)
 	if !ok {
-		writeErr(w, apierror.Unauthorized("auth_required", ""))
 		return
 	}
 	if err := playlists.BuildSystemPlaylists(r.Context(), h.pool, h.logger, user.ID, time.Now(), h.dataDir); err != nil {