Telegram plugin: surface reply_to_message (quoted message) in the inbound <channel> tag

**Plugin:** telegram (claude-channel-telegram), v0.0.6

## Problem

Inbound Telegram messages are forwarded to the Claude session as a `` tag. When the user quote-replies to an earlier message in Telegram, that reply linkage is **not** included in the tag. As a result the model cannot tell which earlier message the user is responding to, and in multi-topic conversations it tends to attach to the most recent context — picking up the wrong thread even though the user explicitly used Telegram's reply feature to disambiguate.

## Note

The data is already available: the server reads `ctx.message.reply_to_message` (currently only used internally to detect replies to the bot). It is simply not surfaced into the inbound tag.

## Request

Include the quoted-message reference in the inbound `` tag, e.g.:

`reply_to_message_id=""` and ideally a short `reply_to_excerpt=""`.

This lets the model resolve the user's intended context and makes Telegram's native reply/quote feature work as a thread disambiguator — especially valuable when one assistant juggles several parallel topics with the user.

## Optional

Surface forwarded-message origin (`forward_origin`) the same way, for the same reason.

In the claude-channel-telegram plugin, start at inbound handling that reads ctx.message.reply_to_message and trace where the tag is assembled. Add the requested quoted-message reference fields, preserve the existing reply-to-bot behavior, and confirm that the resulting tag distinguishes a quoted message; forwarded origin is optional.

索引モデルが issue の本文から書いたものです。