feat: add codex provider support and optional forwarding workflow (localhost:3000 -> public url for remote debugging)

[dimkk]

Summary

This PR adds first-class Codex CLI support to CCBot and improves Telegram delivery reliability for long-running
sessions.

What’s included

• Added provider abstraction with CCBOT_PROVIDER:
  • claude (existing behavior)
  • codex (new)
• Added CCBOT_AGENT_COMMAND as the primary command entrypoint for new windows
  (kept CLAUDE_COMMAND as backward-compatible alias)
• Added Codex session mapping from rollout logs (~/.codex/sessions or CCBOT_CODEX_SESSIONS_PATH)
• Added support for forwarding unknown slash commands to active session (/status, /permissions, etc.)
• Added private chat mode support (single stable binding to tmux window ccbot)

Port Forwarding

• Added startup port forwarding via CLI flag:
  • --forward 3000
  • --forward 3000 --forward 5173
• Added tunnel provider chain:
  • ngrok -> cloudflared -> localhost.run (ssh)
• Sends forwarded public links to allowed users and pins that message
• Properly unpins on shutdown (post_stop)
• Fixed localhost.run parsing:
  • ignores https://admin.localhost.run
  • supports real public tunnel domains (*.localhost.run, *.lhr.life)
• Fixed localhost.run startup by removing ssh -N (ensures tunnel URL is actually emitted in non-interactive mode)

Reliability / Delivery

• Added line-level trace logging from session line -> Telegram message:
  • enqueue/send/edit events
  • trace age + queue wait timing
• Simplified delivery path by removing Codex catch-up/turbo drop mode:
  • no low-priority message dropping
  • preserves 1:1 message flow semantics
• Kept queue ordering and status behavior intact

Docs

• Updated README with:
  • provider switching (claude / codex)
  • --forward usage and lifecycle
  • Codex session resume example (CCBOT_AGENT_COMMAND='codex resume <session-id>')

Notes on compatibility

• Existing Claude flow remains supported.
• CLAUDE_COMMAND still works, but CCBOT_AGENT_COMMAND is now preferred.
• No migration required for existing state files.

Validation

Ran targeted tests for updated areas:

• tests/ccbot/test_config.py
• tests/ccbot/test_main.py
• tests/ccbot/test_port_forward.py
• tests/ccbot/test_codex_mapper.py
• tests/ccbot/test_session.py

All passed locally.