feat(playlists): share playlists with revocable read-only links

services/api/migrations/00016_playlist_sharing.sql

@@ -0,0 +1,7 @@
+-- +goose Up
+ALTER TABLE playlists ADD COLUMN share_id uuid;
+CREATE UNIQUE INDEX playlists_share_id_idx ON playlists (share_id) WHERE share_id IS NOT NULL;
+
+-- +goose Down
+DROP INDEX playlists_share_id_idx;
+ALTER TABLE playlists DROP COLUMN share_id;