feat(i18n): add header menu keys to all locales

Adds the header.* keys introduced by the header rewrite (enter, search
users, staff, mod/admin panel, command center, logs, logo generator,
dashboard/profile/settings links, credits/duckets/diamonds, ...) to all
25 message files. Values are translated where available and fall back to
English otherwise.

The working tree files had been re-serialized with escaped unicode
(\uXXXX); this commit restores literal UTF-8 so the diff shows only the
content change instead of a full-file rewrite.

src/messages/it.json

@@ -42,7 +42,26 @@
 		"tagline": "Un mondo virtuale online dove puoi creare il tuo avatar, fare amicizia, chattare, creare stanze e molto altro!",
 		"login": "Accedi",
 		"or": "Oppure",
-		"createAccount": "Crea un account"
+		"createAccount": "Crea un account",
+		"enter": "Enter",
+		"searchUsers": "Cerca utenti...",
+		"staff": "Staff",
+		"modPanel": "Mod panel",
+		"adminPanel": "Admin panel",
+		"commandCenter": "Centro comandi",
+		"logs": "Logs",
+		"logoGenerator": "Logo generator",
+		"myDashboard": "La mia pagina",
+		"myProfile": "Il mio profilo",
+		"userSettings": "Impostazioni",
+		"twoFactor": "Two-factor",
+		"loginActivity": "Login activity",
+		"friendRequests": "Richieste di amicizia",
+		"more": "+{count} altri",
+		"logout": "Esci",
+		"credits": "Crediti",
+		"duckets": "Duckets",
+		"diamonds": "Diamanti"
 	},
 	"footer": {
 		"copyright": "© {year} - {hotel} è un progetto educativo senza scopo di lucro"