Bytecode-aware optimization

Zen Studio Live limits final bytecode to 65,519 bytes.

1. Compile and record exact size/load first.

2. Remove unused const strings/images/tables; they still occupy data bytes.

3. Narrow const element types when safe.

4. Factor genuinely repeated executable blocks into functions.

5. Simplify duplicate menu rendering/lookup logic.

6. Keep stack depth in view while flattening giant expressions.

7. Recompile and regression-test after each reduction.

Unused user functions and combos can be removed by optimization, but unused const data remains material.