chore: remove share opinion sidebar prompt

Delete the share opinion dialog and its sidebar trigger.
Remove the related toast and footer action wiring.
Clean up unused i18n entries in all supported languages.

packages/ui/src/lib/i18n/messages/es.ts

@@ -23,13 +23,6 @@ export const dict: Record<I18nKey, string> = {
   "pwa.installPrompt.dismiss": "Descartar",
   "pwa.installPrompt.started": "Instalación iniciada",
   "pwa.installPrompt.installed": "OpenChamber se instaló",
-  "shareOpinion.actions.shareOpinion": "Compartir opinión",
-  "shareOpinion.actions.bookCall": "Reservar llamada",
-  "shareOpinion.actions.shortSurvey": "Encuesta breve",
-  "shareOpinion.dialog.title": "Comparte tu opinión",
-  "shareOpinion.toast.title": "Ayuda a dar forma a OpenChamber",
-  "shareOpinion.toast.description": "Cuenta qué es útil, confuso o falta para ayudar a definir lo que viene después.",
-  "sessions.sidebar.footer.actions.shareOpinion": "Compartir opinión",
   "layout.mainTab.chat": "Chat",
   "layout.mainTab.plan": "Plan",
   "layout.mainTab.diff": "Diff",