New: optionally surface error/fatal logs as on-screen notifications

[swashbuck]

Subject of the enhancement

Add an opt-in mode where error and fatal log messages are shown as on-screen push notifications, not only written to the browser console.

Course authors assemble courses in the authoring tool and are generally not developers. When a plugin or config problem fires an error (for example ERROR: Branching: Spoor is misconfigured. Branching requires _spoor._tracking._shouldStoreAttempts = true), it goes to the console only. Authors do not open the console, so the misconfiguration ships unnoticed. There is currently no way for a non-developer to discover that the course logged an error.

Your environment

• Framework: confirmed against v5.56.2 (the relevant code is long-standing)
• Browser/device: not browser-specific

Current behaviour

error and fatal messages are written to the browser console only (when _logging._console is enabled). A non-developer never sees them.

Expected behaviour

With a new opt-in flag, error/fatal logs additionally appear as on-screen notifications so an author can read the message and forward it to a developer. The console output is unchanged, so the developer workflow is untouched.

Suggested Fix

logging.js already triggers log and log:<level> events for this exact purpose ("Allow error reporting plugins to hook and report to logging systems"), so the hook exists. This adds a first-party consumer behind a flag that calls notify.push().

Extend the existing _logging block in config.schema.json with a nested _notify object, disabled by default so published courses and learners are unaffected:

"_logging": {
  "_notify": {
    "_isEnabled": false,
    "_level": "error",
    "_timeout": 15000
  }
}

• _isEnabled (default false): off unless the author opts in.
• _level (error or fatal, default error): minimum level to notify.
• _timeout (default 15000): generous, because each push is manually dismissible.

Behaviour notes:

• Only the message args are shown, not a stack trace. The console call stack is a devtools feature, not part of the log payload.
• Notifications are deduplicated by message. error is not covered by _warnFirstOnly, so a repeating error could otherwise flood the push queue (max 2 visible at once).
• Early errors are buffered until the notify UI is ready, then flushed.
• Timeout is per-notification, so this needs no change to the notify subsystem.

Out of scope: rewriting plugin error text into plain language (messages are shown as authored so the developer gets exact wording), and any persistent error badge or log panel.

Screenshots

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Posted via collaboration with Claude Code