Evidence for the LocalisedString suite design

The design is ../../localised-string.md. These files are the record its decisions and figures come from, kept as written during drafting on 2026-10-30. File references in them name sibling checkouts as ../sdmxlib and ../statcatlib, read at the commits the design names.

File	What it holds
localised-string-notes.md	The SDMX IM audit, wire spellings and the storage benchmark
bench_istring.py	Storage: dict[str, str] against stored value objects
bench_lookup.py, bench_lookup_fair.py	Lookup cost of the value-type candidates on sdmxlib's InternationalString
bench_struct_dunders.py	msgspec.Struct with __bool__, __str__, __format__ and a validating __post_init__
bench_post_init.py	The cost of __post_init__ split into the hook and the tag check
bench_final_type.py, bench_final_split.py	The final value type, the text type check and msgspec.structs.replace
brainstorm-round1.md	Goldfish brainstorm, six lenses
final-review.md	Final review, seven lenses
final-review-2.md	Review of the final choices, four lenses

The reports were written against drafts, so their line numbers refer to earlier versions of the design, and some of their findings were resolved differently. The design is authoritative.

Run a benchmark from an sdmxlib checkout on feat/gh-280-language-tags or later: uv run python -I <path to script>. bench_lookup_fair.py loads bench_lookup.py from beside itself.