Added data label for backend.

server/migrations/20260131020351_add_label.sql

@@ -0,0 +1,17 @@
+-- Add migration script here
+
+-- Create Label
+CREATE TABLE label
+(
+    id bigint NOT NULL GENERATED ALWAYS AS IDENTITY ( INCREMENT 1 START 1 ),
+    name text NOT NULL
+);
+
+-- Alter variant table
+ALTER TABLE public.variant
+    ADD label_id bigint,
+    ADD variant_description text,
+    ADD CONSTRAINT variant_label_id_fkey
+       foreign key (label_id)
+           references unit(id)
+           ON DELETE NO ACTION;