feat: add Codex CLI support, dual Discord bots, and Discord typing fix

- Add Codex as alternative agent type (agentType: 'codex' per group)
- Codex container runner with session resume and 100-turn limit
- Dual Discord bot support (DISCORD_BOT_TOKEN + DISCORD_CODEX_BOT_TOKEN)
- Each bot handles only its agentType's registered groups
- Discord typing indicator refreshes every 8s (was single-shot, expired after ~10s)
- Agent runner 100-turn limit to prevent infinite bot-to-bot loops
- Apple Container runtime support (convert-to-apple-container skill)
- Session commands (/compact) support
- DB migration for agent_type column

package.json

@@ -21,6 +21,7 @@
   "dependencies": {
     "better-sqlite3": "^11.8.1",
     "cron-parser": "^5.5.0",
+    "discord.js": "^14.18.0",
     "pino": "^9.6.0",
     "pino-pretty": "^13.0.0",
     "yaml": "^2.8.2",