Add web client and containerized deployment stack

Web client:

- Added React + TypeScript + Vite + Tailwind application in web/.

- Implemented auth, chat list, chat messages, typing indicators, file uploads, and voice recording/playback.

- Added typed API layer, Zustand stores, and realtime websocket hook integration.

Containerization:

- Added backend Dockerfile and project .dockerignore.

- Added web multi-stage Dockerfile with nginx static hosting and API/WS reverse proxy.

- Added full docker-compose stack with postgres, redis, minio, backend, worker, mailpit, and web.

- Added MinIO bucket bootstrap init job and updated README with Docker quick-start.

web/src/store/chatStore.ts

@@ -0,0 +1,47 @@
+import { create } from "zustand";
+import { getChats, getMessages } from "../api/chats";
+import type { Chat, Message } from "../chat/types";
+
+interface ChatState {
+  chats: Chat[];
+  activeChatId: number | null;
+  messagesByChat: Record<number, Message[]>;
+  typingByChat: Record<number, number[]>;
+  loadChats: () => Promise<void>;
+  setActiveChatId: (chatId: number | null) => void;
+  loadMessages: (chatId: number) => Promise<void>;
+  prependMessage: (chatId: number, message: Message) => void;
+  setTypingUsers: (chatId: number, userIds: number[]) => void;
+}
+
+export const useChatStore = create<ChatState>((set, get) => ({
+  chats: [],
+  activeChatId: null,
+  messagesByChat: {},
+  typingByChat: {},
+  loadChats: async () => {
+    const chats = await getChats();
+    set({ chats, activeChatId: chats[0]?.id ?? null });
+  },
+  setActiveChatId: (chatId) => set({ activeChatId: chatId }),
+  loadMessages: async (chatId) => {
+    const messages = await getMessages(chatId);
+    set((state) => ({
+      messagesByChat: {
+        ...state.messagesByChat,
+        [chatId]: [...messages].reverse()
+      }
+    }));
+  },
+  prependMessage: (chatId, message) => {
+    const old = get().messagesByChat[chatId] ?? [];
+    if (old.some((m) => m.id === message.id)) {
+      return;
+    }
+    set((state) => ({
+      messagesByChat: { ...state.messagesByChat, [chatId]: [...old, message] }
+    }));
+  },
+  setTypingUsers: (chatId, userIds) =>
+    set((state) => ({ typingByChat: { ...state.typingByChat, [chatId]: userIds } }))
+}));