test: add regression test for issue #37 undefined variable bug

[Unisay]

Add golden test reproducing the scenario from issue #37 where monadic code with nested do-blocks and function composition previously generated invalid Lua code with undefined variable references (Bind11).

The test verifies correct compilation of:

• Nested monadic do-blocks
• Bind dictionary threading through local scopes
• Function composition within array literals

Current compilation generates valid Lua code with properly scoped local variables, suggesting the bug has been fixed. This test serves as a regression guard.