fix: Frozen environment and assorted other fixes

[esolithe]

This PR covers the following (mainly the tweaks which lets Esobold embed Lumara):

• Moving the chat message and similar objects to a higher level scope to prevent crashes during runs (to do with the initialisation of specs to run the modules)
• Updated theme.js to use relative paths.
• Fixed some missing sys.exit imports / references
• Added some logging with traces to allow easier debugging of loading errors
• Updated the module checking code to handle frozen environments, giving a bit more latitude to the naming and trying several methods to validate they are in the environment before writing them off. Note: This work was mostly AI led even though I did refine it a few times. The current state is the middle ground I found to keep it generic but work for the more restrictive environments.

I've mostly opened this for visibility so you're aware of the fixes I've found. It would be nice if they can be upstreamed, but given there is AI usage for point five that's your call 👍

If you have any questions, please let me know.