refactor(orders): replace local state machine with minimal cache

Strip store/orders.ts to a thin local cache with setOrders and
updateOrder only. Remove all client-side state transition logic,
actor validation, chat sync, notification generation, and wallet
integration — these are now handled by the backend API.

Fix components/order-actions.tsx and stores that depended on
the removed order store methods (markDisputed, autoTimeout*).

store/disputes.ts

@@ -108,11 +108,6 @@ export const useDisputeStore = create<DisputeState>((set, get) => {
         return { decision: deny(403, "仅订单参与方可发起争议") }
       }
 
-      const markResult = useOrderStore.getState().markDisputed(input.orderId, actor)
-      if (!markResult.decision.ok) {
-        return { decision: markResult.decision }
-      }
-
       const createdAt = new Date().toISOString()
       const dispute: DisputeRecord = {
         id: generateId("disp"),