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 now
falls in two buckets, both governed by internal/ui.

Status lines and confirmations (config init, config set, database
delete) go through the ui message methods: styled, and --quiet silences
them. The data a command exists to produce is written plain, since a
marker would corrupt a table or a parsed document: the version, info, and
remote info reports, the snapshot list table, config get values, and the
--json documents. --quiet silences the human reports and tables but never
the config get value or the --json documents, which a script depends on.
The database delete confirmation prompt is always shown; it is an
interactive exchange the operator must see.

The pure-cli commands reach internal/ui through a small commandUI helper
that builds a ui.Writer on the command's stdout in quiet mode when
--quiet is set. NewForTesting now supplies a UI writer so the quiet gate
is never nil. The README output-style section states the resulting rule.

Model: opus-4-8

internal/cli/version.go

@@ -2,11 +2,11 @@ package cli
 
 import (
 	"fmt"
-	"io"
 	"runtime"
 
 	"github.com/spf13/cobra"
 	"sneak.berlin/go/vaultik/internal/globals"
+	"sneak.berlin/go/vaultik/internal/ui"
 )
 
 // NewVersionCommand creates the version command
@@ -17,16 +17,25 @@ func NewVersionCommand() *cobra.Command {
 		Long:  `Print version, git commit, and build information for vaultik.`,
 		Args:  cobra.NoArgs,
 		Run: func(cmd *cobra.Command, _ []string) {
-			writeVersion(cmd.OutOrStdout())
+			writeVersion(commandUI(cmd))
 		},
 	}
 
 	return cmd
 }
 
-// writeVersion prints the version report. It takes a writer rather than
-// using os.Stdout directly so the output can be asserted on in tests.
-func writeVersion(w io.Writer) {
+// writeVersion prints the version report through the UI writer. The
+// report is the output this command exists to produce, so it is written
+// plain (markers would corrupt the aligned report) via the writer's
+// underlying stdout; --quiet silences it like any other non-error
+// output.
+func writeVersion(out *ui.Writer) {
+	if out.Quiet() {
+		return
+	}
+
+	w := out.Out()
+
 	_, _ = fmt.Fprintf(w, "vaultik %s\n", globals.Version)
 	_, _ = fmt.Fprintf(w, "  commit:     %s\n", globals.Commit)
 	_, _ = fmt.Fprintf(w, "  build date: %s\n", globals.CommitDate)