fix(telegram): warn on oversized media

docs/telegram.md

@@ -33,13 +33,14 @@ Status: ready for bot-mode use with grammY (long-polling by default; webhook sup
 - Sees only messages sent after it’s added to a chat; no pre-history access.
 - Cannot DM users first; they must initiate. Channels are receive-only unless the bot is an admin poster.
 - File size caps follow Telegram Bot API (up to 2 GB for documents; smaller for some media types).
+- Inbound media saved to disk is capped at 5MB (hard limit).
 - Typing indicators (`sendChatAction`) supported; native replies are **off by default** and enabled via `telegram.replyToMode` + reply tags.
 
 ## Planned implementation details
 - Library: grammY is the only client for send + gateway (fetch fallback removed); grammY throttler is enabled by default to stay under Bot API limits.
 - Inbound normalization: maps Bot API updates to `MsgContext` with `Surface: "telegram"`, `ChatType: direct|group`, `SenderName`, `MediaPath`/`MediaType` when attachments arrive, `Timestamp`, and reply-to metadata (`ReplyToId`, `ReplyToBody`, `ReplyToSender`) when the user replies; reply context is appended to `Body` as a `[Replying to ...]` block (includes `id:` when available); groups require @bot mention or a `routing.groupChat.mentionPatterns` match by default (override per chat in config).
 - Outbound: text and media (photo/video/audio/document) with optional caption; chunked to limits. Typing cue sent best-effort.
-- Config: `TELEGRAM_BOT_TOKEN` env or `telegram.botToken` required; `telegram.groups` (group allowlist + mention defaults), `telegram.allowFrom`, `telegram.groupAllowFrom`, `telegram.groupPolicy`, `telegram.mediaMaxMb`, `telegram.replyToMode`, `telegram.proxy`, `telegram.webhookSecret`, `telegram.webhookUrl`, `telegram.webhookPath` supported.
+- Config: `TELEGRAM_BOT_TOKEN` env or `telegram.botToken` required; `telegram.groups` (group allowlist + mention defaults), `telegram.allowFrom`, `telegram.groupAllowFrom`, `telegram.groupPolicy`, `telegram.replyToMode`, `telegram.proxy`, `telegram.webhookSecret`, `telegram.webhookUrl`, `telegram.webhookPath` supported.
   - Ack reactions are controlled globally via `messages.ackReaction` + `messages.ackReactionScope`.
   - Mention gating precedence (most specific wins): `telegram.groups.<chatId>.requireMention` → `telegram.groups."*".requireMention` → default `true`.
 
@@ -57,7 +58,6 @@ Example config:
     allowFrom: ["123456789"], // direct chat ids allowed (or "*")
     groupPolicy: "allowlist",
     groupAllowFrom: ["tg:123456789", "@alice"],
-    mediaMaxMb: 5,
     proxy: "socks5://localhost:9050",
     webhookSecret: "mysecret",
     webhookPath: "/telegram-webhook",