feat(heartbeat): добавить Product Hunt как источник трендов

[NickStr11]

Контекст

Heartbeat v2 сканирует HN + GitHub Trending + Reddit. Добавить Product Hunt для более полной картины AI/Tech трендов.

Задача

Добавить Product Hunt launches в heartbeat модуль. Парсить через RSS или веб-скрейпинг (аналогично существующим источникам).

Acceptance Criteria

• Product Hunt launches парсятся (топ-5 за период)
• Формат вывода консистентен с HN/GitHub/Reddit
• Тесты обновлены, coverage не просел ниже 90%
• Graceful fallback если Product Hunt недоступен

Файлы

• tools/heartbeat/main.py
• tools/heartbeat/tests/

Owner

Jules (S size, паттерн аналогичен Reddit PR #18)

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[google-labs-jules]

Jules is on it. When finished, you will see another comment and be able to review a PR.

[github-actions]

🚀 Jules has accepted the task and it has been added to the queue!

[google-labs-jules]

Ready for a review! A PR has been created.