081 ecology pass ran mechanism

// ECOLOGY TEST: @pass_ran should be added by transforms, not hardcoded externally
//
// ISSUE: The "@pass_ran(\"transform\")" annotation is hardcoded in multiple places.
// Transforms should ADD this annotation themselves, and the walker should just
// check for its presence - not have the string scattered everywhere.
//
// This test verifies that:
// 1. Transforms properly add @pass_ran to prevent re-transformation
// 2. Nested transforms don't infinite loop
// 3. The mechanism works for user-defined transforms too

~import std/control
~import std/io

// Use nested control flow - each should only transform ONCE
~for(0..2)
! each i |> if(i > 0)
    | then |> std/io:print.ln("nested transform")
    | else |> std/io:print.ln("first iteration")
| done |> std/io:print.ln("done")