feat/design the move smart contract for the stack

[leeduckgo]

create table public.micro_ai_saas (
  id bigint generated by default as identity not null,
  "user" text null,
  prompt text null,
  task_type text null default 'llm'::text,
  solution text null,
  solver text null,
  fee bigint null default '0'::bigint,
  fee_unit text null default 'ldg'::text,
  tx text null default ''::text,
  created_at timestamp with time zone not null default now(),
  solved_at timestamp without time zone null,
  signature text null,
  unique_id uuid null default gen_random_uuid (),
  solver_type jsonb null default '[]'::jsonb,
  constraint micro_ai_saas_pkey primary key (id)
) TABLESPACE pg_default;