WhatsNew: clippy clean across the workspace

docs/WhatsNew.md

@@ -140,3 +140,7 @@ Queue back to user-direction: two next-milestone candidates queued on the roadma
 ## 2026-05-13 — Documentation and drift-test hygiene
 
 Two internal cleanups while you were away. Compiler documentation builds without warnings now — twenty-three stale cross-references between docs and code were repaired. And the test that guards DESIGN.md against drifting out of sync with the schema is now stricter — it scans only the schema section, so an anchor that happens to appear somewhere else in the document can no longer mask a missing entry in the canonical reference.
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+## 2026-05-14 — Compiler now builds clean under `cargo clippy`
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+Sixty-one linter warnings across the whole compiler workspace are gone — the project now builds clean under `cargo clippy --workspace --all-targets`. Most were documentation: multi-line comments that the linter misread as bullet lists, and orphan doc-blocks left over from the recent test relocations. A handful were idiomatic refactors (`.expect_err` instead of `.err().expect()`, dropped redundant closures, collapsed nested pattern matches, two manual `Default` impls replaced by `#[derive(Default)]`). Three places kept the original code with an inline `#[allow]` and a one-line reason, where the linter's suggestion would have lost meaning. All tests stay green, the documentation build stays warning-free, and all three benchmark scripts pass at the existing baselines — confirming the sweep touched no semantics.