feat(cli): positional account grammar, account show, TTY remove confirm; drop whitelist flags

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

go.mod

@@ -10,6 +10,7 @@ require (
 	github.com/emersion/go-message v0.18.2
 	github.com/emersion/go-sasl v0.0.0-20241020182733-b788ff22d5a6
 	github.com/emersion/go-smtp v0.24.0
+	github.com/mattn/go-isatty v0.0.20
 	modernc.org/sqlite v1.53.0
 )
 
@@ -27,7 +28,6 @@ require (
 	github.com/erikgeiser/coninput v0.0.0-20211004153227-1c3628e74d0f // indirect
 	github.com/google/uuid v1.6.0 // indirect
 	github.com/lucasb-eyer/go-colorful v1.3.0 // indirect
-	github.com/mattn/go-isatty v0.0.20 // indirect
 	github.com/mattn/go-localereader v0.0.1 // indirect
 	github.com/mattn/go-runewidth v0.0.19 // indirect
 	github.com/muesli/ansi v0.0.0-20230316100256-276c6243b2f6 // indirect