Feature request: Discord plugin should show typing indicator during full processing time

When the Discord plugin receives a message and Claude is processing (researching, thinking, calling tools), the typing indicator only appears briefly at the start, then disappears. There's a long pause with no feedback before the response appears. This makes it look like the bot has stalled.

Expected behavior: The typing indicator should persist and refresh on an interval for the entire duration between receiving a message and sending the response, similar to how OpenClaw handles this with typingMode and typingIntervalSeconds.

Current behavior: Typing indicator fires briefly, disappears, long pause, then response appears.

Suggested implementation: Send a typing indicator as soon as a message is received, and refresh it every few seconds until the response is sent. A configurable interval (e.g. typingIntervalSeconds) would be ideal.