Upgrade to LibLouis 3.39.0 and carry the full table metadata

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Upgrades the bundled LibLouis to 3.39.0 and reworks translation table metadata to carry what LibLouis actually declares. Breaking API changes — this is a 3.0.0, not the 2.1.0 the upgrade alone would have been.

LibLouis 3.39.0

liblouis.dll rebuilt from the 3.39.0 tag for Windows x64 with UCS-4 (UTF-32) widechars, and all bundled tables refreshed: 478 files, up from 472. New: en-nz-g1.utb and en-nz-g2.ctb (English as used in New Zealand, following Braille Authority of New Zealand Aotearoa Trust policy), ht-g1.utb with ht-frenchcompatibility.uti (Haitian Creole), ru-math.uti (Russian mathematical braille), fr-bfu-comp6-puncs-math.uti. None removed. The release also brings an overhauled Portuguese grade 1 table, better back-translation for the Bulgarian, Italian and Biblical Hebrew tables, and 5000+ new English grade 3 hyphenation patterns.

The two Dutch tables generated from m4 templates are carried over from 3.38.0: their .in templates are unchanged since that tag and the expansion rule is a bare m4 -G with no defines, so the output is identical.

Two of the three nmake patches this build needed in 3.38.0 are gone — the missing stdbool.h include and the strncasecmp shim were fixed upstream, which also gained a Windows NMAKE CI job. One remains, and it is an upstream bug worth reporting separately: windows/include/config.h defines PACKAGE_VERSION as "liblouis-3.39.0" where autotools yields a bare "3.39.0", so an unpatched nmake build returns a version string lou_version() callers cannot parse.

Why the metadata rework

TranslationTable described a table as having one language and one type. LibLouis does not work that way — the manual states plainly that "the same key may appear multiple times in a table":

• 22 tables declare several languages. he-IL.utb (Israeli braille) declares Hebrew, Arabic and English, and was discoverable only as Hebrew. ancient-languages-us.utb declares thirty-six.
• 8 tables declare two types. The Swedish and Elfdalian 8-dot tables are both computer and literary; only the first survived.
• Whole fields were discarded: region, grade, system, variant, version, locale, unicode-range and #-index-name were never read.
• Two tables were missing from tables.json entirely. The jsonifier matched metadata lines by substring, so the word "language" inside the display names of ancient-languages-us.utb and ancient-languages-borger.utb shadowed their real language fields and both were filtered out as having no language. Fixed in Read the full table metadata, and every value of a repeated key liblouis-jsonify-tables#1, which this depends on.

What changed

Languages and TableTypes are lists, replacing the scalar Language and TableType. IndexName, Region, Grade, System, Variant, Version, Locale and UnicodeRange are new. Grade is a string because 1.2, 1.3, 1.4 and 1.5 are real grades.

language and region are RFC 4647 extended language ranges, not plain codes — he-IL.utb declares region: *-IL, IPA.utb declares language: *-fonipa. The new LanguageRange class implements the extended filtering of RFC 4647 §3.3.2, the rule LibLouis itself applies in lou_findTable, and FindByLanguage now matches that way instead of comparing strings. So FindByLanguage("en-GB") finds the tables declaring plain en, and FindByLanguage("ar") finds Israeli braille. Matching is asymmetric: a bare akk does not find a table declaring only akk-Latn.

TranslationTable becomes a sealed record rather than a readonly record struct. A record's synthesized equality compares list members by reference, so keeping the struct would have quietly dropped the value equality the type documents; Equals and GetHashCode are written out and compare the lists element by element.

Also added: TableCollection.FindByRegion(), FindComputer(), FindByGrade(); TranslationTable.MatchesLanguage(), MatchesRegion(), IsOfType(), IsGrade().

ListLanguages() gains curated English names for the codes .NET cannot name — jpa, oar, obm, xdm among the ones the multi-language tables bring in — and a test now fails if any bundled language would reach a UI as a bare code.

Migrating from 2.x

• table.Language == "en" → table.MatchesLanguage("en")
• table.TableType → table.TableTypes, or table.IsOfType(...) / IsLiteraryBraille()
• FindByFileName(...) returns a nullable reference now, so table.Value.DisplayName → table.DisplayName
• Positional construction → object initializer; FileName and DisplayName are required

Full notes in CHANGELOG.md.

Verification

130 tests pass in Debug and Release, including new ones that compile and translate with every table added or at risk in this release, and a guard that GetVersion() reports 3.39.x so a refreshed table set can never ship next to a stale DLL. dotnet pack produces a package carrying all 478 tables. A build with GITHUB_ACTIONS=true (warnings-as-errors, analyzers) is clean.

Merge order

accessmind/liblouis-jsonify-tables#1 is merged, so this is unblocked. The committed tables.json was re-generated from LLJT master after that merge and is byte-identical, so the two are in sync. Next step after this merges is tagging v3.0.0.