Route direct-stdout command output through internal/ui (closes #149)

version, info, remote info, config, and database delete wrote plain text straight to stdout, so they were unstyled and ignored --quiet. Output is now governed by internal/ui in two buckets. Status lines and confirmations (config init, config set, the database delete prompt) go through the ui message methods and are silenced by --quiet. The data a command exists to produce is written plain -- the version/info/remote-info reports, the snapshot list table, config get values, and the --json documents -- and is never suppressed, since a script depends on it and a marker would corrupt a table or document. The database delete confirmation prompt is always shown. Pure-cli commands reach ui through a small commandUI helper.

Model: opus-4-8

internal/vaultik/vaultik.go

@@ -215,6 +215,7 @@ func NewForTesting(storage storage.Storer) *TestVaultik {
 			Stdout:  stdout,
 			Stderr:  stderr,
 			Stdin:   stdin,
+			UI:      ui.NewWithColor(stdout, false),
 		},
 		Stdout: stdout,
 		Stderr: stderr,