Before we implement more specific/user friendly erro messages in MDL-83147, we need to do some discovery. Primarily, we should focus on things like:

1. Identifying common error types users (students, teachers, admins) are likely to encounter, such as potential errors from misconfiguration by the admin, account token limits, server errors, unknown errors etc.
2. How the current providers (and possibly the future providers slated for this increment) return those errors.
3. Analyse how/where (at a high level) we might structure handling in the AI subsystem, so that if a provider returns a common error type from #1, we can map the provider specific error message to some pre-defined language string from Moodle, which is what is displayed to the user. If debugging is enabled, we would also want to provide some additional information. (I would also assume we will retain the existing generic error message as a fallback for any messages we don't provide handling for).
4. Identify any risks, major issues etc we may run into.

One example scenario is a student attempts to summarise the page of a book activity, the provider has been misconfigured with an incorrect API key, so the provider returns an error to that effect, and we want to surface a different, user friendly, error message to the user (eg, very roughly, "The AI provider has not been correctly configured by the site administrator, please try again later or contact site support).

Important note: This is a discovery exercise. No implementation should be completed in this issue, we are simply performing some discovery and analysis so that we can identify potential approaches, any gotchas/potential issues etc. You should read MDL-83147 and any comments first, as there is some relevant information there.

This task is assigned 2 points of effort, so this should be taken into consideration for the time spent on this task (we should dedicate no more than 1 day to complete this).