discord plugin: fetch_messages fails for channel IDs exceeding float64 precision (JavaScript snowflake truncation)

Bug Description

The \fetch_messages\ tool in the \plugin:discord@claude-plugins-official\ plugin fails when the \chat_id\ parameter is a Discord snowflake ID that exceeds JavaScript's \Number.MAX_SAFE_INTEGER\ (2^53 - 1 ≈ 9×10^15).

Discord snowflake IDs are 64-bit integers and can be as large as ~9.2×10^18. When \fetch_messages\ internally converts the \chat_id\ string to a JavaScript \Number\, precision is lost and the resulting value is no longer a valid snowflake, causing the Discord API to reject it.

Error

\\\
fetch_messages failed: Invalid Form Body
channel_id[NUMBER_TYPE_COERCE]: Value "undefined" is not snowflake.
\\\

Reproduction

1. Use a Discord channel whose ID exceeds 9007199254740991 (any sufficiently large snowflake)
2. Call \fetch_messages\ with that \chat_id\
3. The call fails with the error above

Expected Behavior

\fetch_messages\ should pass \chat_id\ as a string throughout, without numeric conversion. All Discord snowflake IDs should be treated as opaque strings.

Notes

• Inbound message delivery works correctly (snowflake arrives as a string via WebSocket push)
• Only \fetch_messages\ (which does an HTTP GET) is affected
• The same bug may affect \reply\, \react\, and \edit_message\ for such channel IDs — worth checking

Environment

• Plugin: \plugin:discord@claude-plugins-official\
• Platform: macOS (Darwin 25.3.0)