fix: change unknown source message log from error to debug level

[Copilot]

During development with HMR tooling (Vite, etc.), PostMessageTransport logs console.error for every benign message from dev servers and browser extensions, obscuring actual errors.

Changes:

• Changed console.error to console.debug in PostMessageTransport when ignoring messages from unknown sources (line 80)
• Maintains identical security behavior (still ignores unknown sources)
• Parsing failures remain at console.error level (line 88)

// Before: noisy during development
if (eventSource && event.source !== this.eventSource) {
  console.error("Ignoring message from unknown source", event);
  return;
}

// After: hidden by default, available when debugging
if (eventSource && event.source !== this.eventSource) {
  console.debug("Ignoring message from unknown source", event);
  return;
}

Original prompt

---

This section details on the original issue you should resolve

<issue_title>PostMessageTransport logs noisy console.error for expected unknown sources during development</issue_title>
<issue_description>When using AppBridge with Vite dev server (or similar HMR tooling), the console is filled with error logs:

Ignoring message from unknown source MessageEvent {isTrusted: true, data: {…}, origin: 'http://localhost:8081', ...}

This comes from src/message-transport.ts:80:

console.error("Ignoring message from unknown source", event);

Cause

This is a dev-only issue. During development:

• Vite sends HMR (hot module reload) messages to all windows
• Browser extensions may also send messages
• AppBridge's PostMessageTransport receives these and logs errors

In production builds without dev servers, this noise doesn't occur.

Problem

Using console.error for expected/benign dev-time events creates noise that obscures real errors during development - exactly when clear console output matters most.

Suggested Fix

Change to console.debug so it's hidden by default but still available when needed:

console.debug("Ignoring message from unknown source", event);

Alternatively, filter known noise sources (e.g., messages containing vite or hot-update in the data).

---

🦉 Drafted with Claude Code and reviewed by @olaservo</issue_description>

Comments on the Issue (you are @copilot in this section)

• Fixes PostMessageTransport logs noisy console.error for expected unknown sources during development #237

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commit: 4f1ba25

[antonpk1]

👍