add registration

migrations/20260913130000_add_team_registration.sql

@@ -0,0 +1,13 @@
+-- +goose Up
+ALTER TABLE teams
+    ADD COLUMN captain_email TEXT NOT NULL DEFAULT '',
+    ADD COLUMN participants_count INTEGER NOT NULL DEFAULT 0 CHECK (participants_count >= 0),
+    ADD COLUMN registration_delivery_id TEXT,
+    ADD CONSTRAINT teams_registration_delivery_unique UNIQUE (game_id, registration_delivery_id);
+
+-- +goose Down
+ALTER TABLE teams
+    DROP CONSTRAINT teams_registration_delivery_unique,
+    DROP COLUMN registration_delivery_id,
+    DROP COLUMN participants_count,
+    DROP COLUMN captain_email;