i18n complete: all 16 components translated (CZ/HE/RU/UA)

- Custom i18n provider with React Context + localStorage
- Hebrew RTL support (dir=rtl on html)
- All pages + components use t() calls
- FullCalendar + dates locale-aware
- Language selector in Settings wired to context

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

apps/tasks/app/chat/page.tsx

@@ -3,6 +3,7 @@
 import { useState, useRef, useEffect } from "react";
 import { useRouter } from "next/navigation";
 import { useAuth } from "@/lib/auth";
+import { useTranslation } from "@/lib/i18n";
 
 interface ChatMessage {
   id: string;
@@ -13,6 +14,7 @@ interface ChatMessage {
 
 export default function ChatPage() {
   const { token, user } = useAuth();
+  const { t, locale } = useTranslation();
   const router = useRouter();
   const [messages, setMessages] = useState<ChatMessage[]>([]);
   const [input, setInput] = useState("");
@@ -20,6 +22,8 @@ export default function ChatPage() {
   const messagesEndRef = useRef<HTMLDivElement>(null);
   const inputRef = useRef<HTMLTextAreaElement>(null);
 
+  const timeLocale = locale === "ua" ? "uk-UA" : locale === "cs" ? "cs-CZ" : locale === "he" ? "he-IL" : "ru-RU";
+
   useEffect(() => {
     if (!token) {
       router.replace("/login");
@@ -63,7 +67,7 @@ export default function ChatPage() {
       const assistantMsg: ChatMessage = {
         id: (Date.now() + 1).toString(),
         role: "assistant",
-        content: data.reply || data.message || "Omlouvám se, nemohl jsem zpracovat vaši zprávu.",
+        content: data.reply || data.message || t("chat.processError"),
         timestamp: new Date(),
       };
       setMessages((prev) => [...prev, assistantMsg]);
@@ -71,7 +75,7 @@ export default function ChatPage() {
       const errorMsg: ChatMessage = {
         id: (Date.now() + 1).toString(),
         role: "assistant",
-        content: "Chat asistent je momentálně nedostupný. Zkuste to prosím později.",
+        content: t("chat.unavailable"),
         timestamp: new Date(),
       };
       setMessages((prev) => [...prev, errorMsg]);
@@ -100,8 +104,8 @@ export default function ChatPage() {
           </svg>
         </div>
         <div>
-          <h1 className="font-semibold">AI Asistent</h1>
-          <p className="text-xs text-muted">Zeptejte se na cokoliv ohledně vašich úkolů</p>
+          <h1 className="font-semibold">{t("chat.title")}</h1>
+          <p className="text-xs text-muted">{t("chat.subtitle")}</p>
         </div>
       </div>
 
@@ -114,9 +118,9 @@ export default function ChatPage() {
                 <path strokeLinecap="round" strokeLinejoin="round" d="M8 12h.01M12 12h.01M16 12h.01M21 12c0 4.418-4.03 8-9 8a9.863 9.863 0 01-4.255-.949L3 20l1.395-3.72C3.512 15.042 3 13.574 3 12c0-4.418 4.03-8 9-8s9 3.582 9 8z" />
               </svg>
             </div>
-            <p className="text-muted text-lg font-medium">Začněte konverzaci</p>
+            <p className="text-muted text-lg font-medium">{t("chat.startConversation")}</p>
             <p className="text-muted text-sm mt-1">
-              Napište zprávu a AI asistent vám pomůže s úkoly
+              {t("chat.helpText")}
             </p>
           </div>
         )}
@@ -139,7 +143,7 @@ export default function ChatPage() {
                   msg.role === "user" ? "text-blue-200" : "text-muted"
                 }`}
               >
-                {msg.timestamp.toLocaleTimeString("cs-CZ", { hour: "2-digit", minute: "2-digit" })}
+                {msg.timestamp.toLocaleTimeString(timeLocale, { hour: "2-digit", minute: "2-digit" })}
               </p>
             </div>
           </div>
@@ -168,7 +172,7 @@ export default function ChatPage() {
             value={input}
             onChange={(e) => setInput(e.target.value)}
             onKeyDown={handleKeyDown}
-            placeholder="Napište zprávu..."
+            placeholder={t("chat.placeholder")}
             rows={1}
             className="flex-1 px-4 py-3 border border-gray-300 dark:border-gray-600 rounded-2xl bg-white dark:bg-gray-800 focus:ring-2 focus:ring-blue-500 focus:border-transparent outline-none resize-none text-sm"
             style={{ maxHeight: "120px" }}
@@ -177,7 +181,7 @@ export default function ChatPage() {
             onClick={handleSend}
             disabled={loading || !input.trim()}
             className="p-3 bg-blue-600 hover:bg-blue-700 disabled:opacity-50 text-white rounded-full transition-colors flex-shrink-0"
-            aria-label="Odeslat"
+            aria-label={t("chat.send")}
           >
             <svg className="w-5 h-5" fill="none" viewBox="0 0 24 24" stroke="currentColor" strokeWidth={2}>
               <path strokeLinecap="round" strokeLinejoin="round" d="M12 19l9 2-9-18-9 18 9-2zm0 0v-8" />