feat: port scenario 903 select-pool flow

packages/infra/prisma/migrations/20260730002000_add_select_pool/migration.sql

@@ -0,0 +1,17 @@
+CREATE TABLE "select_pool" (
+    "id" SERIAL PRIMARY KEY,
+    "unique_name" VARCHAR(20) NOT NULL,
+    "owner_user_id" TEXT,
+    "general_id" INTEGER,
+    "reserved_until" TIMESTAMP(3),
+    "info" JSONB NOT NULL
+);
+
+CREATE UNIQUE INDEX "select_pool_unique_name_key"
+    ON "select_pool"("unique_name");
+CREATE UNIQUE INDEX "select_pool_general_id_key"
+    ON "select_pool"("general_id");
+CREATE INDEX "select_pool_owner_user_id_idx"
+    ON "select_pool"("owner_user_id");
+CREATE INDEX "select_pool_reserved_until_general_id_idx"
+    ON "select_pool"("reserved_until", "general_id");