Adds qbz_i18n::mark() (identity, extraction-only) and applies it at the
definition sites of literals later translated through t(variable):
release-type classifier, discover section labels, artist release-section
titles + month names, label jump tabs, and audio settings dropdown tables.
Fixes the discover_prefs double-t() (label_for now returns the marked
literal, translated once at the consumer).
cc
POSIX locale precedence is LC_ALL > LC_MESSAGES > LANG. resolve_auto
previously only checked LC_MESSAGES and LANG; add LC_ALL as the
highest-priority env var, skipping it when empty. Extend the
resolve_auto test (env-mutation serialized via the existing Mutex).
cc
Implement the frontend-agnostic translation layer test-first:
- plural.rs: PluralRule parsing nplurals + the two expressions our
locales use ((n != 1), (n > 1)); index(n) selects the form, with a
safe English default for anything unrecognized.
- po.rs: Catalog::parse handles the header entry, msgid/msgid_plural/
msgstr/msgstr[N], multi-line continuations, and \n \t \" \\
escapes; empty msgstr means no translation (get returns None so
callers fall back to English). Reads Plural-Forms from the header.
- lib.rs: 5 catalogs embedded via include_str! and lazily parsed
(OnceLock); AtomicU8 language state; set_language/current_language/
resolve_auto (LC_MESSAGES then LANG -> 2-letter prefix); t/tn/t_args/
tf with left-to-right {} substitution and English fallback.
17 unit tests, all green via cargo test -p qbz-i18n. Content tests use
inline fixtures since the bundled .po files are header-only for now.
cc
Add new no-dependency qbz-i18n crate to the workspace members.
Frontend-agnostic translation catalog per ADR-006 (reusable by
Slint/TUI/headless; no slint or tauri deps).
cc
vicrodh