Put the language in diagnostics.

src/card.ts

@@ -43,7 +43,7 @@ import {
   REPO_URL
 } from './const.js';
 import './editor.js';
-import { localize } from './localize/localize.js';
+import { getLanguage, localize } from './localize/localize.js';
 import './patches/ha-camera-stream.js';
 import './patches/ha-hls-player.js';
 import './patches/ha-web-rtc-player.ts';
@@ -1369,6 +1369,7 @@ export class FrigateCard extends LitElement {
           ha_version: this._hass.config.version,
           card_version: CARD_VERSION,
           frigate_version: Object.fromEntries(frigateVersionMap),
+          lang: getLanguage(),
           ...(this._rawConfig && { config: this._rawConfig }),
         },
       });

src/localize/localize.ts

@@ -7,7 +7,7 @@ const languages: any = {
   pt_BR: pt_BR,
 };
 
-export function localize(string: string, search = '', replace = ''): string {
+export function getLanguage(): string {
   const canonicalizeLanguage = (language?: string | null): string | null => {
     if (!language) {
       return null;
@@ -16,7 +16,7 @@ export function localize(string: string, search = '', replace = ''): string {
   };
 
   // Try the HA language first...
-  let lang;
+  let lang: string | null = null;
   const HALanguage = localStorage.getItem('selectedLanguage');
   if (HALanguage) {
     const selectedLanguage = canonicalizeLanguage(JSON.parse(HALanguage));
@@ -34,9 +34,11 @@ export function localize(string: string, search = '', replace = ''): string {
       }
     }
   }
+  return lang || 'en';
+}
 
-  // Default to English is there's still no language setting.
-  lang = lang || 'en';
+export function localize(string: string, search = '', replace = ''): string {
+  const lang = getLanguage();
   let translated: string;
 
   try {