feat(i18n): enhance locale support and add under-construction messages

- Updated Header.tsx to use current locale in navigation links for proper routing
- Increased MiniSparkline chart dimensions in market-stats.tsx for better visibility
- Added under-construction translations for market, about, and prices pages in en.json and pt.json
- Minor formatting adjustments with added blank lines across multiple components

These changes improve internationalization and user experience by ensuring locale-aware navigation and providing informative placeholders for upcoming features.

components/Header.tsx

@@ -12,16 +12,17 @@ import { ThemeToggle } from "./theme-toggle";
 import { LanguageSwitcher } from "./language-switcher";
 import { MobileMenu } from "./mobile-menu";
 import { cn } from "@/lib/utils";
-import { useTranslations } from "next-intl";
+import { useTranslations, useLocale } from "next-intl";
 import Link from "next/link";
 
 export default function Header() {
   const t = useTranslations("header.nav");
+  const locale = useLocale();
 
   const links = [
-    { href: "/market", label: t("market") },
-    { href: "/sobre", label: t("about") },
-    { href: "/precos", label: t("prices") },
+    { href: `/${locale}/market`, label: t("market") },
+    { href: `/${locale}/sobre`, label: t("about") },
+    { href: `/${locale}/precos`, label: t("prices") },
   ];
 
   return (