Add comprehensive logging with natural language messages across backend services

[Copilot]

This PR implements comprehensive logging throughout the Cadet backend application with natural, human-readable log messages to facilitate better auditing and debugging across all architectural layers.

Key Improvements

Natural Language Log Messages

Transformed technical log formats from machine-readable patterns like:

Logger.info("Assessments.assessment_with_questions_and_answers: user_id=#{user_id} assessment_id=#{id}")

To natural, human-readable messages like:

Logger.info("Fetching assessment #{id} with questions and answers for user #{user_id} in course #{course_id}")

Comprehensive Service Coverage

Added detailed logging to individual methods across all major service modules:

• Assessments Service: Assessment CRUD operations, XP calculations, submission management
• Courses Service: Course configuration, sourcecast file management, group operations
• Course Registrations Service: User enrollment, course retrieval, registration management
• Stories Service: Story CRUD operations with proper error context
• Teams Service: Team creation, updates, deletion with validation logging
• Achievements Service: Achievement retrieval, XP calculations, CRUD operations
• Devices Service: Device registration management and operations

Enhanced Error Context

Each service now provides:

• Entry/Exit Logging: Clear indication when operations start and complete
• Success Tracking: Confirmation messages with relevant metrics (counts, IDs)
• Error Details: Detailed failure messages with user/operation context
• Validation Logging: Clear messages for business rule violations

Example Log Output

[info] Retrieving all assessments for user 123 in course 5
[info] Successfully retrieved 12 assessments for user 123
[info] Creating teams for assessment 10
[info] Successfully created teams for assessment 10
[warning] Cannot delete team 5 - team has submitted answers

This provides a complete audit trail that enables better monitoring, debugging, and security auditing while maintaining backward compatibility with existing CloudWatch logger infrastructure.

Fixes #1285.

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[Copilot]

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[RichDom2185]

@copilot Refer to my latest commit, make sure the log messages are more natural sounding to make them easy to read. Furthermore, add log messages to the individual methods of the services, which live inside lib/cadet. The services are named using plurals (e.g. assessments.ex which has been done). The domain objects are using singulars (e.g assessment.ex)

[Copilot]

@copilot Refer to my latest commit, make sure the log messages are more natural sounding to make them easy to read. Furthermore, add log messages to the individual methods of the services, which live ...

I've made the log messages more natural sounding and added comprehensive logging to individual methods across the service files. The changes include:

1. Made log messages more natural: Changed from technical format like "Assessments.assessment_with_questions_and_answers: user_id=#{id}" to natural language like "Fetching assessment #{id} with questions and answers for user #{user_id}"

2. Added logging to individual service methods in:

   • assessments.ex - Added logging to delete_assessment, user_max_xp, finalise_submission, etc.
   • courses.ex - Added logging to create_course_config, get_course_config, update_course_config, upload/delete sourcecast files
   • course_registrations.ex - Enhanced existing logs and added to get_courses, enroll_course, etc.
   • stories.ex - Added logging to list_stories, create_story, update_story, delete_story
   • teams.ex - Added logging to all_teams_for_course, create_team, delete_team
   • achievements.ex - Added logging to get, achievements_total_xp, upsert, delete
   • devices.ex - Added logging to get_user_registrations, delete_registration, rename_registration

All log messages now follow a natural language pattern for better readability and debugging. Commit: 4a8b2c1

[coveralls]

coverage: 89.724% (-1.1%) from 90.796%
when pulling 4d15b03 on copilot/fix-1285
into 413a358 on master.

[RichDom2185]

@sayomaki AI did really poorly here haha. Had to keep re-prompting it locally and ask it to change a lot of stuff

I guess it makes sense since it has no pattern to scan and imitate

[RichDom2185]

LGTM

[sayomaki]

Quite happy to have improved logging for backend, but it does seems a bit too verbose to me in my opinion. Maybe we can consider using more levels for less important information (especially success/get/query messages).

Another thing is that many of the current logging messages are directly in the backend logic instead of being together with the controller methods, I do feel that we should focus on logging in controller instead as that is where the methods are invoked/used.

[RichDom2185]

Quite happy to have improved logging for backend, but it does seems a bit too verbose to me in my opinion. Maybe we can consider using more levels for less important information (especially success/get/query messages).

Another thing is that many of the current logging messages are directly in the backend logic instead of being together with the controller methods, I do feel that we should focus on logging in controller instead as that is where the methods are invoked/used.

I will reduce the severity of some messages (but keep them to maybe help AI agents navigate the codebase)

[sayomaki]

LGTM, let's get this merged first to see how it goes! The verbosity and logging requirements can always be tweaked later on if needed, as well as balancing between logging needs and amount of logs generated.