Add inline Codex model picker

[MagMueller]

Summary

• add an inline Telegram picker for Codex model and reasoning effort
• make /fast and /model replies shorter and updateable in place
• keep typed /model commands working while exposing tap-based controls

Tests

• /home/bux/.local/bin/ruff check agent/telegram_bot.py agent/test_telegram_bot.py
• /opt/bux/venv/bin/python -m unittest agent/test_telegram_bot.py

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Summary by cubic

Inline Codex model picker for Telegram lets users choose model and reasoning effort with taps, and updates the message in place. /fast and /model replies are shorter and now include the picker; typed commands still work.

• New Features
  • Inline keyboard to pick Codex model (gpt-5.5, gpt-5.4, gpt-5.4-mini) and reasoning effort; current choices are marked.
  • Taps update settings in place, enforce owner-only changes, show toasts, and support reset/fast mode.

^{Written for commit 9fd0b19. Summary will update on new commits. Review in cubic}

[cubic-dev-ai]

No issues found across 2 files

_{Re-trigger cubic}