feat: phase 2 — i18n messages EN/FR (--lang, AM_LANG/LANG, catalogue tr/tr_fmt, REPL lang) (closes #74)

src/lib.rs

@@ -30,6 +30,7 @@ pub mod events;
 pub mod help;
 pub mod history;
 pub mod hooks;
+pub mod i18n;
 pub mod installers;
 pub mod lab;
 pub mod models;
@@ -85,6 +86,9 @@ fn real_main() -> i32 {
         return code;
     }
     let cli = cli::Cli::parse();
+    // Issue #74: resolve the output language before anything else so even
+    // config errors are localized; the REPL can switch it at runtime.
+    i18n::set_lang(i18n::resolve(cli.lang));
     match app::App::from_cli(cli) {
         Ok(app) => {
             // Issue #53: enforce the session retention at every startup