feat(i18n): implement language switching and localization support

- Remove i18next configuration and dependencies
- Add language switcher component
- Integrate language change functionality with cookies
- Update translations for English and Persian
- Modify layout and page components to support dynamic language rendering
- Refactor Tailwind CSS configuration for custom colors

src/locales/translates.ts

@@ -0,0 +1,57 @@
+import en from './en';
+import fa from './fa';
+
+// Universal getCookie function
+export function getCookie(name: string): string | undefined {
+  if (typeof window !== 'undefined') {
+    // Client-side
+    const match = document.cookie.match(
+      new RegExp('(^| )' + name + '=([^;]+)'),
+    );
+    return match ? decodeURIComponent(match[2]) : undefined;
+  } else {
+    // Server-side (Next.js App Router)
+    try {
+      // Dynamically import to avoid errors in client bundle
+      const { cookies } = require('next/headers');
+      return cookies().get(name)?.value;
+    } catch {
+      return undefined;
+    }
+  }
+}
+
+// Universal setCookie function to change language
+export function changeLanguage(lang: TLocales, days = 365) {
+  if (typeof window !== 'undefined') {
+    // Client-side
+    const expires = new Date(Date.now() + days * 864e5).toUTCString();
+    document.cookie = `lang=${encodeURIComponent(lang)}; expires=${expires}; path=/`;
+  } else {
+    // Server-side (Next.js App Router)
+    try {
+      const { cookies } = require('next/headers');
+      cookies().set('lang', lang, { path: '/', maxAge: days * 24 * 60 * 60 });
+    } catch {
+      // No-op on server if not available
+    }
+  }
+}
+
+export const locales = {
+  en: en as Translates,
+  fa,
+} as Record<TLocales, Translates>;
+
+export const translates = (key: keyof Translates): string | (() => string) => {
+  const lang = (getCookie('lang') || 'en') as TLocales;
+  return locales[lang][key] || locales.en[key] || key;
+};
+
+export const t = (key: keyof Translates) => translates(key);
+
+export type TLocales = 'en' | 'fa';
+
+export type Translates = {
+  [K in keyof typeof en]: string | (() => string);
+};