Add persistent start-again bot action

[pirajoke]

Summary

• add a persistent localized Start again action to the Telegram reply keyboard
• route it through the existing safe /start flow without clearing learning progress
• cover all eight interface locales and update keyboard contracts

Checks

• .venv/bin/python -m unittest discover -s tests (1232 passed, 3 skipped)
• .venv/bin/python -m compileall -q bot.py mydictionary tests
• git diff --check

[chatgpt-codex-connector]

Codex Review Summary

This comment shows the latest Codex review activity on this pull request.

Review	Status	Commit	Review trigger
📝 Code Review	✅ Completed 2026-09-21T20:55:07.011820Z	726556a	PR opened

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