Add category selector to jokes apps

[DenisValeev]

Summary

• add a category dropdown to the random jokes app UI and style it to match existing controls
• rebuild the jokes deck based on the selected category so navigation and punchline reveal work per bucket
• surface the same category selector in both "all jokes" tables and extend the renderer to combine text and category filters

Testing

• node --check apps/jokes/app.js
• node --check apps/jokes/render-all.js

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https://chatgpt.com/codex/tasks/task_e_68d4b4113a488328aea8043662afb44d