Supports multiple programming problems

Currently, the blind coding website supports only a single programming language at a time, limiting user flexibility and challenge variety. To improve usability and enhance the coding experience, we need to add support for multiple programming languages.

**Expected Outcome:**
Users should be able to attempt blind coding challenges in multiple programming languages, enhancing accessibility and improving engagement.

No files, tests, or entry points are identified in the issue. Start by locating how the website selects its current programming language and runs blind coding challenges, then define the supported-language scope and how users choose among them. Done means users can attempt challenges in multiple languages and the behavior is covered by appropriate tests.

Written by the indexing model from the issue text.