feat(VocabService, localization, VocabLessonView): extend assistant wait feedback and timeout duration

- Increased the timeout duration for the language assistant from 30 seconds to 120 seconds to accommodate longer processing times.
- Added new localization strings across multiple languages (Cebuano, German, English, Spanish, French) to provide user feedback during the assistant's wait period, enhancing clarity and user experience.
- Implemented a visual waiting indicator in VocabLessonView to inform users that the assistant is still processing their request, improving overall interaction quality.

frontend/src/i18n/locales/de/socialnetwork.json

@@ -697,6 +697,9 @@
                 "languageAssistantInputPlaceholder": "Stelle eine Frage zur Lektion oder schreibe einen eigenen Satz zum Korrigieren.",
                 "languageAssistantSend": "An Sprachassistent senden",
                 "languageAssistantSending": "Antwort wird geholt ...",
+                "languageAssistantWaitingTitle": "Der Sprachassistent arbeitet noch.",
+                "languageAssistantWaitingBody": "Lokale Modelle wie Ollama brauchen manchmal einige Sekunden, besonders wenn das Modell erst geladen wird.",
+                "languageAssistantWaitingElapsed": "Wartezeit: {seconds} s",
                 "languageAssistantError": "Der Sprachassistent konnte gerade nicht antworten.",
                 "languageAssistantPresetExplainStart": "Erkläre mir bitte die wichtigsten Muster und die Grammatik in der Lektion",
                 "languageAssistantPatternHint": "Nutze dabei besonders dieses Muster",