ActionView::Template::Error: Mysql2::Error: Invalid JSON text in argument 1 to function json_contains: "Missing a closing quotation mark in string." at position 20. (ActionView::Template::Error)

## Error

```
Invalid JSON text in argument 1 to function json_contains: "Missing a closing quotation mark in string." at position 20. (Mysql2::Error)
```

## Stack trace

```
mysql2/client.rb:151 in _query
mysql2/client.rb:151 in block in Mysql2::Client#query
mysql2/client.rb:150 in Thread.handle_interrupt
mysql2/client.rb:150 in query
active_record/connection_adapters/mysql2/database_statements.rb:100 in block (2 levels) in ActiveRecord::ConnectionAdapters::Mysql2::DatabaseStatements#raw_execute
active_record/connection_adapters/abstract_adapter.rb:1027 in block in ActiveRecord::ConnectionAdapters::AbstractAdapter#with_raw_connection
active_support/concurrency/null_lock.rb:9 in synchronize
active_record/connection_adapters/abstract_adapter.rb:999 in with_raw_connection
active_record/connection_adapters/mysql2/database_statements.rb:98 in block in ActiveRecord::ConnectionAdapters::Mysql2::DatabaseStatements#raw_execute
active_support/notifications/instrumenter.rb:58 in instrument
```

## Tracking Details
- **Project**: exercism-rails
- **Sentry**: [ActionView::Template::Error: Mysql2::Error: Invalid JSON text in argument 1 to function json_contains: "Missing a closing quotation mark in string." at position 20. (ActionView::Template::Error)](https://thalamus-ai.sentry.io/issues/146635688/)
- **Culprit**: TracksController#index
- **First seen:** Sep 12, 2026

The failure is reported from TracksController#index; begin with that entry point and follow the shown query path through active_record/connection_adapters/mysql2/database_statements.rb and mysql2/client.rb. Reproduce or isolate the malformed JSON input behind json_contains, then verify TracksController#index renders without the Mysql2 JSON error.

Written by the indexing model from the issue text.