feat(uploads): match release groups with MusicBrainz and AcoustID

docs/data-model.md

@@ -140,9 +140,20 @@ CREATE TABLE upload_batches (           -- одна «пачка» загруз
   created_at  timestamptz NOT NULL DEFAULT now()
 );
 
+CREATE TABLE upload_release_groups (
+  id           uuid PRIMARY KEY,
+  batch_id     uuid NOT NULL REFERENCES upload_batches(id) ON DELETE CASCADE,
+  grouping_key text NOT NULL,           -- ключ первичной группировки, после подтверждения тегов не меняется
+  artist       text NOT NULL DEFAULT '',
+  album        text NOT NULL DEFAULT '',
+  cover_path   text,                    -- обложка только этого релиза
+  UNIQUE (batch_id, grouping_key)
+);
+
 CREATE TABLE upload_files (
   id               uuid PRIMARY KEY,
   batch_id         uuid NOT NULL REFERENCES upload_batches(id) ON DELETE CASCADE,
+  release_group_id uuid REFERENCES upload_release_groups(id) ON DELETE SET NULL,
   author_id        uuid NOT NULL REFERENCES users(id),
   status           upload_status NOT NULL,
   original_name    text NOT NULL,