* fix: remove sensitive send scope from reply and forward shortcuts
Remove mail:user_mailbox.message:send from the required scopes of
+reply, +reply-all, and +forward shortcuts. This scope is sensitive
and may not be granted, while these shortcuts default to saving
drafts and do not strictly require it.
* fix: validate send scope dynamically when --confirm-send is set
Add validateConfirmSendScope() to check mail:user_mailbox.message:send
in the Validate phase when --confirm-send is used, preventing the
"draft created but send failed" scenario. Add regression tests for
+reply, +reply-all, and +forward.
