Pass inbound files to Codex as local path context

[evgyur]

Summary

• include the local absolute path in text-file attachment context sent to Codex
• pass non-image, non-text inbound files through as local-path references instead of dropping them
• update controller tests to cover text-file path context and binary-file local-path handoff

Why

For Telegram/Discord Codex cockpit usage on the same host, the most reliable contract is:

• inbound files are saved locally
• Codex receives the local path and can work with that file directly

This avoids relying on outbound attachment re-delivery as the primary path.

Tests

• npm run typecheck
• npx vitest run src/controller.test.ts