Smoke-testing invented German dictations exposed that `ae`/`oe`/`ue`
spellings collapsed lexical recall (e.g. "Hyperlipidaemie" → garbage,
"Hyperlipidämie" → correct). normalize() now folds ä→ae, ö→oe, ü→ue,
ß→ss; it is applied only in lexical.rs (both corpus index and query),
so the path is symmetric under either spelling. The embedding path
(raw text for bge-m3) is intentionally untouched.
eval.rs inject_errors case 2 changed from umlaut-deletion (ä→a) to the
realistic ASCII-digraph variant (ä→ae) so the eval harness exercises —
and guards against regression of — exactly this failure class.
TDD: failing tests first; normalize_tests 5/5, full suite 44/0.
Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>
Brummel
8348e33264