i18n (cs): Effect > Pathfinder > Add reads "Sjednotit", keyed by the effect id

The key "Add" is shared by Effect > Pathfinder > Add (PathfinderOp::Unite),
the File Info button and a label in the raster effects dialog. One plain row
cannot fit all three: "Přidat" is right for the button, but the Pathfinder
effect unites shapes, so it reads "Sjednotit".

- cs.tsv: `@id pathfinder.add` = "Sjednotit"; the plain "Add" row stays
  "Přidat".
- menus.rs: Effect menu items all run effect.apply / effect.dialog, so the
  command id cannot tell them apart. effect_item_label() looks the effect's
  own id up first (an @id row), and "Last Effect: {name}" does the same.
- appearance.rs: the Appearance panel's effect labels use the same lookup.
- i18n/tests.rs: an @id row may now name an effect id as well as a command
  id; czech_reads_as_czech pins Add and pathfinder.add.

No other catalog has an @id row, so their behaviour is unchanged.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

crates/ui-egui/src/i18n/cs.tsv

@@ -370,6 +370,7 @@
 	Zig Zag…	Cikcak…
 	Pathfinder	Operace s cestami
 	Add	Přidat
+@id	pathfinder.add	Sjednotit
 	Intersect	Protnout
 	Exclude	Vyloučit
 	Subtract	Odečíst

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

@@ -161,8 +161,11 @@ fn bundled_catalogs_are_consistent() {
                 assert_eq!(src.ends_with('…'), tr.ends_with('…'), "{}: ellipsis mismatch: {src:?}", l.code);
             }
             if ctx == "@id" {
-                let known =
-                    crate::menus::UI_COMMANDS.iter().any(|c| c.0 == src) || vectorcraft_engine::cmd::command_specs().iter().any(|c| c.id == src);
+                // A command id, or an effect id: Effect menu items share `effect.apply` /
+                // `effect.dialog`, so the effect's own id is what tells them apart.
+                let known = crate::menus::UI_COMMANDS.iter().any(|c| c.0 == src)
+                    || vectorcraft_engine::cmd::command_specs().iter().any(|c| c.id == src)
+                    || vectorcraft_effects::effect_catalog().iter().any(|e| e.id == src);
                 assert!(known, "{}: unknown command id {src:?}", l.code);
             }
         }
@@ -839,6 +842,10 @@ fn czech_reads_as_czech() {
         assert_eq!(trn(cs(), n, "{n} Layer", "{n} Layers"), format!("{n} {word}"));
     }
     assert_eq!(tr_ctx(cs(), "axis", "Both"), "Obě");
+    // "Add" is Unite in Effect › Pathfinder (an `@id` row for the effect id); "Přidat" elsewhere.
+    assert_eq!(tr(cs(), "Add"), "Přidat");
+    assert_eq!(tr_id(cs(), "pathfinder.add", "Add"), "Sjednotit");
+    assert_eq!(tr_id(cs(), "pathfinder.intersect", "Intersect"), "Protnout");
     let nested = "command `object.group` is not available right now: nothing selected";
     assert_eq!(message(cs(), nested), "příkaz `object.group` nyní není k dispozici: nic není vybráno");
 }

crates/ui-egui/src/menus.rs

@@ -1650,7 +1650,7 @@ pub fn display_label(app: &VectorcraftApp, id: &str, label: &str) -> String {
         "effect.last" => match &app.last_effect {
             Some((e, _)) => {
                 let name = vectorcraft_effects::effect_info(e).map(|i| i.label).unwrap_or(e.as_str());
-                fmt(tl!("Last Effect: {name}"), &[("name", tl!(name))])
+                fmt(tl!("Last Effect: {name}"), &[("name", crate::i18n::tr_id(lang, e, name))])
             }
             None => crate::i18n::tr_id(lang, id, label).to_string(),
         },
@@ -1661,6 +1661,19 @@ pub fn display_label(app: &VectorcraftApp, id: &str, label: &str) -> String {
     }
 }
 
+/// The label of an Effect menu item in the UI language, by the effect's own id. Every effect item
+/// runs `effect.apply` or `effect.dialog`, so the command id can't tell them apart; an `@id` row
+/// for the effect id (for example `pathfinder.add`) wins over the plain row of the English label.
+/// `None` when the catalog has no such row, and the plain translation applies.
+fn effect_item_label(id: &str, p: &Value) -> Option<String> {
+    if !matches!(id, "effect.apply" | "effect.dialog") {
+        return None;
+    }
+    let effect = p.get("effect")?.as_str()?;
+    let shown = crate::i18n::tr_id(crate::i18n::current(), effect, "");
+    (!shown.is_empty()).then(|| shown.to_string())
+}
+
 /// Menu slots that are left out while they have nothing to show (unused saved views, recent files,
 /// User Defined swatch and graphic style libraries).
 fn hidden_when_disabled(id: &str) -> bool {
@@ -1793,7 +1806,7 @@ pub fn entry<'a>(app: &VectorcraftApp, it: &'a Item) -> Option<Entry<'a>> {
             Entry::Item(Row {
                 command: Some((id, p)),
                 source: label,
-                label: display_label(app, id, label).into(),
+                label: effect_item_label(id, p).unwrap_or_else(|| display_label(app, id, label)).into(),
                 shortcut: item_shortcut(id, p),
                 enabled,
                 checked,

crates/ui-egui/src/panels/appearance.rs

@@ -160,10 +160,11 @@ fn built_in_effect(id: &str) -> bool {
     catalog().iter().any(|c| c.0 == id)
 }
 
-/// [`effect_label`] as shown: a built-in effect's in the UI language, a plug-in's as it is.
+/// [`effect_label`] as shown: a built-in effect's in the UI language (an `@id` row for the
+/// effect's id wins over the plain row of its English label), a plug-in's as it is.
 fn shown_effect_label(id: &str) -> String {
     match catalog().iter().find(|c| c.0 == id) {
-        Some(c) => tl!(&c.1).to_string(),
+        Some(c) => crate::i18n::t_id(id, &c.1).to_string(),
         None => effect_label(id),
     }
 }