regenerate workflow_mcp_server enum migration on top of staging (0257)

Author: icecrasher321

packages/db/migrations/0257_green_black_bolt.sql

@@ -0,0 +1,3 @@
+-- migration-safe: additive enum value only (no rewrite, no table lock); old app code never
+-- reads or writes 'workflow_mcp_server' rows, so it is invisible during cutover
+ALTER TYPE "public"."workspace_fork_resource_type" ADD VALUE 'workflow_mcp_server' BEFORE 'custom_tool';