[Bug] Debug 'Realm set to' message leaks into chat panel as fake user message

### Platform
Not specified

### App Version
Not specified

### Device Information
Not specified

### Issue Description
A debug/system message is leaking into the chat panel: a message from sender `0x0000...0000` reading `Realm set to \`https://peer.decentraland.org/content\`` appears in chat, right below a normal user message. This looks like an internal realm-change log line being rendered as if it were a chat message from a real user.

### Expected Behavior
Internal/debug status messages (like realm changes) should not be posted into the chat panel as if sent by a user, or should be filtered out of the visible chat log entirely.

### Screenshots / Media
Attached in the reporting Slack thread — shows the chat panel with a message from `0x0000...0000` reading "Realm set to `https://peer.decentraland.org/content`".

### Steps to Reproduce
Not specified — reported by Sebga, forwarded by Dawid. Appears related to a realm change while chat is open.

### Occurrence
Not specified

**Requested by Gon via Slack**