[dylan-sutton-chavez]

Every call becomes a jump inside one block of sections, and recursion turns a shared state with TurnR/UnturnR and undoes it. The nested loop and the generic frames are gone.

• Corpus: geomean 0.867 against main 9b26eb5.
• Bench: -12.2 % instructions. Approved slower cases: class P, class R, fib and t(label) in instructions, plus 67 short programs in memory (the cost of lowering a hot function).
• Release, debug, lang, clippy, make check, test-cli with consistency and test-skill pass.