feat: add bot gateway for remote monitoring via chat platforms

Implement Bot Agent system (Phase 1-4):
- Add bot gateway with IPC communication via Unix socket
- Support 5 chat platforms: Telegram, Discord, Slack, Lark, FB Messenger
- Natural language intent parsing for commands
- Process registry with auto-generated unique names
- Session management and approval workflow
- Bot configuration in zen.json with platform-specific settings

Co-Authored-By: Claude (claude-opus-4-6) <noreply@anthropic.com>

Author: john-zhh

internal/bot/adapters/adapter.go

@@ -0,0 +1,162 @@
+package adapters
+
+import (
+	"context"
+	"time"
+)
+
+// Platform represents a chat platform.
+type Platform string
+
+const (
+	PlatformTelegram    Platform = "telegram"
+	PlatformDiscord     Platform = "discord"
+	PlatformSlack       Platform = "slack"
+	PlatformLark        Platform = "lark"
+	PlatformFBMessenger Platform = "fbmessenger"
+)
+
+// Message represents an incoming message from any platform.
+type Message struct {
+	ID          string            `json:"id"`
+	Platform    Platform          `json:"platform"`
+	ChatID      string            `json:"chat_id"`
+	UserID      string            `json:"user_id"`
+	UserName    string            `json:"user_name"`
+	Content     string            `json:"content"`
+	ReplyTo     string            `json:"reply_to,omitempty"`
+	ThreadID    string            `json:"thread_id,omitempty"`
+	Timestamp   time.Time         `json:"timestamp"`
+	IsMention   bool              `json:"is_mention"`
+	IsDirectMsg bool              `json:"is_direct_msg"`
+	Metadata    map[string]string `json:"metadata,omitempty"`
+}
+
+// OutgoingMessage represents a message to be sent.
+type OutgoingMessage struct {
+	Text    string   `json:"text"`
+	Format  string   `json:"format"` // plain, markdown
+	Buttons []Button `json:"buttons,omitempty"`
+}
+
+// Button represents an interactive button.
+type Button struct {
+	ID    string `json:"id"`
+	Label string `json:"label"`
+	Style string `json:"style"` // primary, secondary, danger
+	Data  string `json:"data"`
+}
+
+// ButtonClick represents a button click event.
+type ButtonClick struct {
+	Platform  Platform `json:"platform"`
+	ChatID    string   `json:"chat_id"`
+	UserID    string   `json:"user_id"`
+	MessageID string   `json:"message_id"`
+	ButtonID  string   `json:"button_id"`
+	Data      string   `json:"data"`
+}
+
+// Adapter is the interface for chat platform adapters.
+type Adapter interface {
+	// Platform returns the platform identifier.
+	Platform() Platform
+
+	// Start starts the adapter and begins listening for messages.
+	Start(ctx context.Context) error
+
+	// Stop stops the adapter.
+	Stop() error
+
+	// SendMessage sends a message to a chat.
+	SendMessage(chatID string, msg *OutgoingMessage) (string, error)
+
+	// SendReply sends a reply to a specific message.
+	SendReply(chatID, replyTo string, msg *OutgoingMessage) (string, error)
+
+	// EditMessage edits an existing message.
+	EditMessage(chatID, msgID string, msg *OutgoingMessage) error
+
+	// DeleteMessage deletes a message.
+	DeleteMessage(chatID, msgID string) error
+
+	// SetMessageHandler sets the handler for incoming messages.
+	SetMessageHandler(handler func(*Message))
+
+	// SetButtonHandler sets the handler for button clicks.
+	SetButtonHandler(handler func(*ButtonClick))
+
+	// BotUserID returns the bot's user ID on this platform.
+	BotUserID() string
+}
+
+// AdapterConfig is the base configuration for adapters.
+type AdapterConfig struct {
+	Enabled         bool     `json:"enabled"`
+	AllowedUsers    []string `json:"allowed_users,omitempty"`
+	AllowedChannels []string `json:"allowed_channels,omitempty"`
+	AllowedChats    []string `json:"allowed_chats,omitempty"`
+}
+
+// IsUserAllowed checks if a user is in the allowed list.
+func (c *AdapterConfig) IsUserAllowed(userID string) bool {
+	if len(c.AllowedUsers) == 0 {
+		return true
+	}
+	for _, u := range c.AllowedUsers {
+		if u == userID {
+			return true
+		}
+	}
+	return false
+}
+
+// IsChatAllowed checks if a chat/channel is in the allowed list.
+func (c *AdapterConfig) IsChatAllowed(chatID string) bool {
+	// Check both channels and chats
+	allowed := append(c.AllowedChannels, c.AllowedChats...)
+	if len(allowed) == 0 {
+		return true
+	}
+	for _, ch := range allowed {
+		if ch == chatID {
+			return true
+		}
+	}
+	return false
+}
+
+// TelegramConfig is the configuration for Telegram adapter.
+type TelegramConfig struct {
+	AdapterConfig
+	Token string `json:"token"`
+}
+
+// DiscordConfig is the configuration for Discord adapter.
+type DiscordConfig struct {
+	AdapterConfig
+	Token         string   `json:"token"`
+	AllowedGuilds []string `json:"allowed_guilds,omitempty"`
+}
+
+// SlackConfig is the configuration for Slack adapter.
+type SlackConfig struct {
+	AdapterConfig
+	BotToken string `json:"bot_token"`
+	AppToken string `json:"app_token"`
+}
+
+// LarkConfig is the configuration for Lark/Feishu adapter.
+type LarkConfig struct {
+	AdapterConfig
+	AppID     string `json:"app_id"`
+	AppSecret string `json:"app_secret"`
+}
+
+// FBMessengerConfig is the configuration for Facebook Messenger adapter.
+type FBMessengerConfig struct {
+	AdapterConfig
+	PageToken   string `json:"page_token"`
+	VerifyToken string `json:"verify_token"`
+	AppSecret   string `json:"app_secret,omitempty"`
+}