ADR 0003 — Telegram: grammY, long polling, plain text, privacy mode on

Status: accepted 2026-09-13. grammY 1.46 (MIT). Long polling (one consumer per token). Plain text, 4 000-char paragraph-aware chunks, fences closed/reopened. message_thread_id in the session key. Allowlist by numeric from.id. Groups: the bot must be a group admin (or privacy mode disabled and the bot re-added), because privacy mode drops plain @mentions; angelia enforces mention itself. Media via getFile (≤20 MB) into <cwd>/.inbox/.