- Switch crate-level #![allow] to #![expect] in main.rs and prune
17 entries the compiler reports as unfulfilled or workspace-allowed.
- Fix the underlying issues rather than allow: source ordering
(mods/uses regrouped), doc_markdown (identifiers backticked),
redundant_type_annotations, map_unwrap_or, unnecessary_wraps.
- Extract feature-gated mod ppe_impl into its own file
tools/cycle_bench/src/ppe/ppe_impl.rs so the mod declaration can
precede the public structs per arbitrary_source_item_ordering.
Net: 35 → 12 expects in main.rs, all load-bearing.
