feat: add a user setting to toggle sidebar chat hover previews (#27632)

Co-authored-by: Tim Baek <tim@openwebui.com>

src/lib/i18n/locales/en-US/translation.json

@@ -428,6 +428,7 @@
 	"Chat forked": "",
 	"Chat history": "",
 	"Chat History": "",
+	"Chat Hover Previews": "",
 	"Chat ID": "",
 	"Chat is too short to compact": "",
 	"Chat moved successfully": "",
@@ -2450,6 +2451,7 @@
 	"Sharing Permissions": "",
 	"Show": "",
 	"Show \"What's New\" Modal on Login": "",
+	"Show a floating preview of recent messages when hovering a chat in the sidebar.": "",
 	"Show admin contact details while an account waits for approval.": "",
 	"Show All": "",
 	"Show all ({{COUNT}} characters)": "",