fix: use translation key as fallback + more translations

src/routes/(app)/c/[id]/+page.svelte

@@ -779,7 +779,7 @@
 		if ($settings.titleAutoGenerate ?? true) {
 			const title = await generateTitle(
 				localStorage.token,
-				$settings?.titleGenerationPrompt ?? $i18n.t('Default titleGenerationPromt') + ' {{prompt}}',
+				$settings?.titleGenerationPrompt ?? $i18n.t("Create a concise, 3-5 word phrase as a header for the following query, strictly adhering to the 3-5 word limit and avoiding the use of the word 'title':") + ' {{prompt}}',
 				$settings?.titleAutoGenerateModel ?? selectedModels[0],
 				userPrompt
 			);