feat(frontend): rebuild chatbot UI to match backend — wider panel, guild context, Indonesian

- Chatbot bubble: 220px → 320px wide, 440px tall; proper header with
  drag handle; quick-prompt row when chat is closed
- ChatPanel: show ALL history (not last 8), Indonesian placeholder/empty
  state/error copy (backend speaks Indonesian), timestamps (id-ID),
  clear-history button, typing indicator bubbles, Enter-to-send
- Send active guildId as context so backend answers reference the real
  server (serverInsights path in chatbot.service)
- GuildId sync from layout → ChatbotProvider via ChatbotGuildSync
- chatbotApi.send(message, guildId) → POST /api/chat {message, context}
  matching BE zod schema (guildId optional)

services/frontend/src/lib/api/chatbot.ts

@@ -2,8 +2,11 @@ import type { ChatbotHistoryRow, ChatbotResponse } from "@/lib/types";
 import { api } from "./client";
 
 export const chatbotApi = {
-  send: (message: string) =>
-    api.post<ChatbotResponse>("/api/chat", { message }),
+  send: (message: string, guildId?: string) =>
+    api.post<ChatbotResponse>("/api/chat", {
+      message,
+      context: guildId ? { guildId } : undefined,
+    }),
 
   getHistory: () =>
     api.get<{ history: ChatbotHistoryRow[]; total: number }>(