i18n: add Turkish (tr) localization

- Add crates/ui-egui/src/i18n/tr.tsv covering all menu strings, commands, UI labels, and status/error messages with standard Turkish vector software vocabulary.
- Register Turkish in LANGUAGES with plural_none and complete_menus: true.
- Support tr, tr-TR, tr_TR.UTF-8, tr-CY locale mapping in lang_from_tag.
- Add Turkish typographic quotation marks in crates/doc/src/setup.rs.
- Add turkish_reads_as_turkish unit test and register tr in KEEPS_MENU_NAMES and COMPLETE_MESSAGES.
- Include RTF diagnostic message with exact TSV escaping.

crates/doc/src/setup.rs

@@ -154,6 +154,7 @@ pub const LANGUAGES: &[(&str, Quotes)] = &[
     ("Polish", Quotes { double: ['„', '”'], single: ['‚', '’'] }),
     ("Czech", Quotes { double: ['„', '“'], single: ['‚', '‘'] }),
     ("Russian", Quotes { double: ['«', '»'], single: ['„', '“'] }),
+    ("Turkish", Quotes { double: ['“', '”'], single: ['‘', '’'] }),
     ("Japanese", Quotes { double: ['「', '」'], single: ['『', '』'] }),
     ("Chinese", Quotes { double: ['“', '”'], single: ['‘', '’'] }),
 ];

crates/ui-egui/src/dialogs/document_setup.rs

@@ -78,6 +78,7 @@ fn unit(d: &Dialog) -> Unit {
     Unit::named(&d.str("units")).unwrap_or_default()
 }
 
+/// The General tab of Document Setup (units, bleed, artboard editing, options).
 fn general(app: &mut VectorcraftApp, ui: &mut egui::Ui, d: &mut Dialog) -> bool {
     let units: Vec<(&str, &str)> = Unit::ALL.iter().map(|u| (u.label(), u.label())).collect();
     choice(ui, d, "units", tl!("Units:"), &units);

crates/ui-egui/src/i18n/mod.rs

@@ -94,7 +94,7 @@ fn plural_polish(n: u64) -> usize {
 }
 
 /// The registry. English first: it is the fallback and the source language.
-pub static LANGUAGES: [LangInfo; 24] = [
+pub static LANGUAGES: [LangInfo; 25] = [
     LangInfo { code: "en", name: "English", source: "", plural: plural_one_other, complete_menus: false, catalog: OnceLock::new() },
     // Greek: the whole interface and the status and error messages, keeping the same names in
     // English as Spanish; every `el-*` locale (including `el-GR` and `el-CY`) resolves here.
@@ -263,6 +263,10 @@ pub static LANGUAGES: [LangInfo; 24] = [
     // English as Spanish; one/other plurals with the partitive after any number but 1 ("2 tasoa").
     // Every `fi-*` locale resolves here.
     LangInfo { code: "fi", name: "Suomi", source: include_str!("fi.tsv"), plural: plural_one_other, complete_menus: true, catalog: OnceLock::new() },
+    // Turkish: the whole interface and the status and error messages, keeping the same names in
+    // English as Spanish; a count takes the singular ("3 katman"), so plurals have one form. Every
+    // `tr-*` locale (including `tr-TR` and `tr-CY`) resolves here.
+    LangInfo { code: "tr", name: "Türkçe", source: include_str!("tr.tsv"), plural: plural_none, complete_menus: true, catalog: OnceLock::new() },
 ];
 
 impl LangInfo {

crates/ui-egui/src/i18n/tests.rs

@@ -870,7 +870,7 @@ fn cs() -> Lang {
 }
 
 /// Languages whose catalogs leave [`MENU_KEEP_AS_IS`] in English.
-const KEEPS_MENU_NAMES: [&str; 17] = ["cs", "de", "el", "es", "fr", "hu", "it", "ja", "ka", "ko", "pl", "pt-br", "ru", "sv", "uk", "vi", "fi"];
+const KEEPS_MENU_NAMES: [&str; 18] = ["cs", "de", "el", "es", "fr", "hu", "it", "ja", "ka", "ko", "pl", "pt-br", "ru", "sv", "uk", "vi", "fi", "tr"];
 
 /// Menu labels the menu-complete catalogs (Czech, German, Spanish, Italian, Japanese, Brazilian Portuguese) show as they are: the product name, a format name, the built-in workspace
 /// names and the perspective grid presets (names, shown untranslated wherever else they appear).
@@ -1190,6 +1190,41 @@ fn finnish_reads_as_finnish() {
     assert_eq!(message(fi(), nested), "komento `object.group` ei ole nyt käytettävissä: mitään ei ole valittu");
 }
 
+/// The Turkish catalog registers under `tr`, claims complete menus and messages, and passes
+/// locale resolution, vocabulary and count formatting checks.
+#[test]
+fn turkish_reads_as_turkish() {
+    assert_eq!(tr_lang().name(), "Türkçe");
+    assert!(tr_lang().complete_menus());
+    assert_eq!(Lang::from_pref("tr"), tr_lang());
+    assert_eq!(Lang::from_pref("TR"), tr_lang());
+    for tag in ["tr", "tr-TR", "tr_TR.UTF-8", "TR-tr", "tr-CY"] {
+        assert_eq!(lang_from_tag(tag), Some(tr_lang()), "{tag}");
+    }
+    for (en, want) in [
+        ("Artboard Tool", "Çalışma Yüzeyi Aracı"),
+        ("Swatches", "Renk Örnekleri"),
+        ("Stroke", "Kontur"),
+        ("Fill", "Dolgu"),
+        ("Direct Selection Tool", "Doğrudan Seçim Aracı"),
+        ("Save As…", "Farklı Kaydet…"),
+        ("Undo", "Geri Al"),
+        ("Close", "Kapat"),
+    ] {
+        assert_eq!(tr(tr_lang(), en), want);
+    }
+    for n in [0, 1, 3, 21] {
+        assert_eq!(trn(tr_lang(), n, "{n} Layer", "{n} Layers"), format!("{n} Katman"));
+    }
+    let nested = "command `object.group` is not available right now: nothing selected";
+    assert_eq!(message(tr_lang(), nested), "`object.group` komutu şu anda kullanılamıyor: hiçbir şey seçilmedi");
+}
+
+/// The [`Lang`] handle for the Turkish catalog.
+fn tr_lang() -> Lang {
+    Lang::from_code("tr").expect("tr registered")
+}
+
 /// Ambiguous English terms keep their intended Vietnamese meaning across UI contexts.
 #[test]
 fn vietnamese_domain_terms_are_consistent() {
@@ -2104,7 +2139,7 @@ fn shared_param_check_errors_are_translated() {
 
 /// Languages whose catalogs cover every status and error message.
 const COMPLETE_MESSAGES: &[&str] =
-    &["cs", "de", "el", "es", "fr", "hu", "it", "ja", "ka", "ko", "pl", "pt-br", "ru", "sv", "uk", "vi", "zh-hans", "zh-hant", "fi"];
+    &["cs", "de", "el", "es", "fr", "hu", "it", "ja", "ka", "ko", "pl", "pt-br", "ru", "sv", "uk", "vi", "zh-hans", "zh-hant", "fi", "tr"];
 
 /// Crates whose error and status messages reach the status bar.
 const MESSAGE_CRATES: &[&str] = &["ui-egui", "engine", "doc", "format", "svg", "pdf", "eps", "text", "plugins", "metafile", "cad", "trace"];

crates/ui-egui/src/widgets.rs

@@ -2864,6 +2864,7 @@ mod combo_keyboard_tests {
 mod button_tests {
     use super::*;
 
+    /// [`flat_button_fit`] preserves minimum width for short labels and expands for long ones.
     #[test]
     fn flat_button_fit_expands_for_long_text() {
         let ctx = egui::Context::default();