fix(mom): private channel messages not being logged

- Add message.groups to required bot events in README
- Add groups:history and groups:read to required scopes in README
- app_mention handler now logs messages directly instead of relying on message event
- Add deduplication in ChannelStore.logMessage() to prevent double-logging
- Remove redundant current message append in agent.ts (already in log)

packages/mom/src/store.ts

@@ -35,6 +35,9 @@ export class ChannelStore {
 	private botToken: string;
 	private pendingDownloads: PendingDownload[] = [];
 	private isDownloading = false;
+	// Track recently logged message timestamps to prevent duplicates
+	// Key: "channelId:ts", automatically cleaned up after 60 seconds
+	private recentlyLogged = new Map<string, number>();
 
 	constructor(config: ChannelStoreConfig) {
 		this.workingDir = config.workingDir;
@@ -107,8 +110,19 @@ export class ChannelStore {
 
 	/**
 	 * Log a message to the channel's log.jsonl
+	 * Returns false if message was already logged (duplicate)
 	 */
-	async logMessage(channelId: string, message: LoggedMessage): Promise<void> {
+	async logMessage(channelId: string, message: LoggedMessage): Promise<boolean> {
+		// Check for duplicate (same channel + timestamp)
+		const dedupeKey = `${channelId}:${message.ts}`;
+		if (this.recentlyLogged.has(dedupeKey)) {
+			return false; // Already logged
+		}
+
+		// Mark as logged and schedule cleanup after 60 seconds
+		this.recentlyLogged.set(dedupeKey, Date.now());
+		setTimeout(() => this.recentlyLogged.delete(dedupeKey), 60000);
+
 		const logPath = join(this.getChannelDir(channelId), "log.jsonl");
 
 		// Ensure message has a date field
@@ -127,6 +141,7 @@ export class ChannelStore {
 
 		const line = JSON.stringify(message) + "\n";
 		await appendFile(logPath, line, "utf-8");
+		return true;
 	}
 
 	/**