[codex] Add Hermes runtime support to Bux

[ShawnPana]

Summary

• add an opt-in Hermes installer and Bux-owned bux-hermes wrapper
• write Bux context into Hermes' auto-loaded $HERMES_HOME/SOUL.md with managed markers while preserving existing persona text
• map Bux's stable bux-hermes run <prompt> adapter to real Hermes --oneshot <prompt>
• add AGENT_HERMES, /hermes, _run_hermes, and BUX_DEFAULT_AGENT routing to the Telegram bot
• let tg_install persist BUX_DEFAULT_AGENT for future BuxFather/cloud default-agent flows
• document the implementation plan and local non-production smoke test

Impact

Hermes can be tested as a third local Bux agent without making it the production default. Existing Claude and Codex flows remain the fallback unless a lane is explicitly switched to Hermes or BUX_DEFAULT_AGENT=hermes is configured.

Validation

• hermes --help and hermes chat --help inspected locally; real Hermes v0.12.0 supports --oneshot, not a run subcommand
• HERMES_BIN="$(command -v hermes)" BUX_HOME="$HOME" ./agent/bux-hermes run "Reply with exactly: bux-hermes-ok" returned bux-hermes-ok
• temp-home installer smoke confirmed uppercase $HERMES_HOME/SOUL.md is preserved/updated and exported to the Hermes process
• python3 -m py_compile agent/telegram_bot.py agent/box_agent.py
• bash -n agent/install-hermes agent/bux-hermes install.sh agent/bootstrap.sh
• python3 -m unittest discover agent
• git diff --check

Notes

agent/bux-hermes is the adapter boundary. If future Hermes changes the non-interactive invocation shape, only that wrapper should need adjustment.