fix(editor): exclude the feed's own text language from its translations

renderFeedTranslations let you add a translation in the same language as
feed.textLanguage — redundant (translating English to English) and
something the event form's own translations section already guards
against (excluded from suggestions, and re-checked on add in case someone
types the code directly rather than picking a suggestion). Ported the same
two-layer guard here, reading textLanguage live via a new getTextLanguage
param so it stays correct if the field changes while the view is open.

Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01DrGeVXHTNNdPi7MCgSageG

Author: hhkaos

apps/editor/src/main.ts

@@ -439,6 +439,7 @@ async function startEditor(repo: string | null): Promise<void> {
         renderFeedTranslations(
           feedState.translations,
           () => ({ title: feedState.title, description: feedState.description }),
+          () => feedState.textLanguage,
           (translations) => {
             feedState.translations = translations;
           },

apps/editor/src/ui/form.ts

@@ -1809,6 +1809,7 @@ function renderLanguagePicker(
 export function renderFeedTranslations(
   initial: Record<string, { title: string; description: string }>,
   getOriginal: () => { title: string; description: string },
+  getTextLanguage: () => string,
   onChange: (translations: Record<string, { title: string; description: string }>) => void,
 ): HTMLElement {
   let translations = { ...initial };
@@ -1909,9 +1910,18 @@ export function renderFeedTranslations(
 
   field.append(
     renderLanguagePicker(
-      () => Object.keys(translations),
+      () => {
+        const textLanguage = getTextLanguage();
+        return [...(textLanguage ? [textLanguage] : []), ...Object.keys(translations)];
+      },
       (lang) => {
-        if (lang in translations) return;
+        const textLanguage = getTextLanguage();
+        const isTextLanguage =
+          textLanguage !== "" && lang.toLowerCase() === textLanguage.toLowerCase();
+        const exists = Object.keys(translations).some(
+          (l) => l.toLowerCase() === lang.toLowerCase(),
+        );
+        if (isTextLanguage || exists) return;
         translations = { ...translations, [lang]: { title: "", description: "" } };
         renderList();
         commit();