Two related fixes for a bug where /new could cause config.yaml to be
sent as a Discord attachment:
1. Add config.yaml to the _media_delivery_denied_paths denylist in
gateway/platforms/base.py. This prevents any accidental delivery of
config.yaml as a native file attachment, matching the existing
protection for .env, auth.json, and credentials/.
2. Reword the tip that triggered this: the tip
'hermes chat --ignore-user-config skips ~/.hermes/config.yaml'
contained a bare home-relative path to config.yaml. When randomly
selected during /new, the extract_local_files() method in
_process_message_background would match ~/.hermes/config.yaml as a
local file path, find it exists, and dispatch it as a native Discord
document attachment.