PassthroughWasmOptimizer
The identity optimizer: returns bytes unchanged at every level — the OptLevel.O0 (passthrough) semantics.
A real seam for the paths that don't run a toolchain: the spike's fake-compiler flow and tests keep a genuine WasmOptimizer to call without dragging in Binaryen. Produces no speedup (the transform is a no-op) — real optimization is the :kuilt-warp-compiler WasmOptimizer impl.