Enable Discord message intents and improve message logging

[Paraguanads]

Enables the necessary Gateway Intents to receive message content and adds INFO logs to facilitate mention diagnostics. Fixes the issue where the bot connects but doesn't respond.

Key changes:

discord.go: Set Identify.Intents (GuildMessages, DirectMessages, MessageContent) and upload relevant logs to INFO.

Quick test:

Rebuild and install, start picoclaw gateway, mention the bot, and check for Raw message events / Received messages in the logs.

[PixelTux]

@Paraguanads could you check if this still applies? If so, could you please resolve the conflict?

[CLAassistant]

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