feat: the library's folders are set in Admin › Library, and changing a folder moves its tracks with it, keeping their plays, likes and playlists (#6129)

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

internal/api/admin_search.go

@@ -79,7 +79,7 @@ func (h *handlers) handleGetSearchSettings(w http.ResponseWriter, r *http.Reques
 		writeErrWithLog(w, h.logger, "admin search settings: get", apierror.Internal(err))
 		return
 	}
-	writeJSON(w, http.StatusOK, searchSettings(s, h.importer.Roots))
+	writeJSON(w, http.StatusOK, searchSettings(s, h.importer.Roots()))
 }
 
 type putSearchSettingsBody struct {
@@ -117,7 +117,7 @@ func (h *handlers) handlePutSearchSettings(w http.ResponseWriter, r *http.Reques
 		writeErr(w, apierror.BadRequest("bad_upgrade_until", "unknown quality "+body.UpgradeUntil))
 		return
 	}
-	if body.ImportRoot != "" && !slices.Contains(h.importer.Roots, body.ImportRoot) {
+	if body.ImportRoot != "" && !slices.Contains(h.importer.Roots(), body.ImportRoot) {
 		writeErr(w, apierror.BadRequest("bad_import_root", "file new music into one of the library's folders"))
 		return
 	}
@@ -136,7 +136,7 @@ func (h *handlers) handlePutSearchSettings(w http.ResponseWriter, r *http.Reques
 		writeErrWithLog(w, h.logger, "admin search settings: put", apierror.Internal(err))
 		return
 	}
-	writeJSON(w, http.StatusOK, searchSettings(s, h.importer.Roots))
+	writeJSON(w, http.StatusOK, searchSettings(s, h.importer.Roots()))
 }
 
 // candidateView is one release a want's last search found.