v0.2.0 — env var rename + standalone MCP mode Every mode flag and knob follows <MODE>_MODE / <MODE>_MODE_<KNOB> now. MCP is independent of API/Telegram/Cron and can coexist (sidecar in non-API modes, /mcp mount inside API). Separate bearer token per surface (API_MODE_TOKEN vs MCP_MODE_TOKEN), no fallback between them. Breaking change: every consumer setting AICODEBOX_MODE_API, AICODEBOX_TELEGRAM_BOT_TOKEN, AICODEBOX_MODE_CRON_FILE, etc., needs to rename to the new shape. No backwards-compat shim — clean break.