feat(cli): architecture picker + post-fetch O/C/Enter menu

When multiple download links are returned (e.g. x32+x64 for consumer
ISOs), an architecture picker is shown before printing the URL.

After the URL is printed, an interactive menu lets the user open the
link in the default browser (O), copy it to the clipboard (C), or exit
(Enter). Menu is suppressed when stdout is not a terminal (piping).

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

cli/main.go

@@ -308,18 +308,42 @@ func runConsumer(productID, query, langName string, noContribute bool) error {
 	}
 
 	fmt.Fprintln(os.Stderr, "")
-	for _, link := range links {
+
+	var selectedURI string
+	if isTerminal() && len(links) > 1 {
+		link, err := pickArchitecture(links)
+		if err != nil {
+			return err
+		}
 		name := urlFilename(link.URI)
-		fmt.Fprintf(os.Stderr, "  %s\n", name)
-		fmt.Fprintf(os.Stderr, "  %s\n", strings.Repeat("─", len(name)))
-		fmt.Println(link.URI) // stdout — stays clean for piping
-		fmt.Fprintln(os.Stderr, "")
+		fmt.Fprintf(os.Stderr, "\n  %s\n", name)
+		fmt.Fprintf(os.Stderr, "  %s\n\n", strings.Repeat("─", len(name)))
+		fmt.Println(link.URI)
+		selectedURI = link.URI
+	} else {
+		for _, link := range links {
+			name := urlFilename(link.URI)
+			fmt.Fprintf(os.Stderr, "  %s\n", name)
+			fmt.Fprintf(os.Stderr, "  %s\n", strings.Repeat("─", len(name)))
+			fmt.Println(link.URI) // stdout — stays clean for piping
+			fmt.Fprintln(os.Stderr, "")
+		}
+		if len(links) == 1 {
+			selectedURI = links[0].URI
+		}
 	}
 
 	if !noContribute {
 		fmt.Fprintln(os.Stderr, "  ✓ Shared with MSDL Web App (https://msdl.tech-latest.com/)")
 		fmt.Fprintln(os.Stderr, "    Opt out: --no-contribute")
 		fmt.Fprintln(os.Stderr, "")
+	}
+
+	if isTerminal() && selectedURI != "" {
+		postFetchMenu(selectedURI)
+	}
+
+	if !noContribute {
 		// Wait up to 5s for the contribution to complete before process exit.
 		done := make(chan struct{})
 		go func() { wg.Wait(); close(done) }()
@@ -359,6 +383,9 @@ func runEval(slug string) error {
 
 	if len(links) == 1 {
 		fmt.Println(links[0].URL)
+		if isTerminal() {
+			postFetchMenu(links[0].URL)
+		}
 		return nil
 	}
 
@@ -377,6 +404,10 @@ func runEval(slug string) error {
 	if err != nil {
 		return err
 	}
-	fmt.Println(links[n-1].URL)
+	selected := links[n-1].URL
+	fmt.Println(selected)
+	if isTerminal() {
+		postFetchMenu(selected)
+	}
 	return nil
 }

cli/picker.go

@@ -5,6 +5,8 @@ import (
 	"fmt"
 	"io"
 	"os"
+	"os/exec"
+	"runtime"
 	"strconv"
 	"strings"
 )
@@ -76,3 +78,79 @@ func pickEvalProduct(products []EvalProduct) (EvalProduct, error) {
 	}
 	return products[n-1], nil
 }
+
+func isTerminal() bool {
+	fi, err := os.Stdin.Stat()
+	if err != nil {
+		return false
+	}
+	return fi.Mode()&os.ModeCharDevice != 0
+}
+
+func pickArchitecture(links []DownloadLink) (DownloadLink, error) {
+	fmt.Fprintln(os.Stderr, "Select architecture:")
+	for i, l := range links {
+		label := l.Architecture
+		if label == "" {
+			label = fmt.Sprintf("link %d", i+1)
+		}
+		fmt.Fprintf(os.Stderr, "  %2d. %s\n", i+1, label)
+	}
+	fmt.Fprint(os.Stderr, "\nChoice: ")
+	n, err := parseChoice(os.Stdin, len(links))
+	if err != nil {
+		return DownloadLink{}, err
+	}
+	return links[n-1], nil
+}
+
+func openInBrowser(rawURL string) error {
+	var cmd *exec.Cmd
+	switch runtime.GOOS {
+	case "windows":
+		cmd = exec.Command("cmd", "/c", "start", "", rawURL)
+	case "darwin":
+		cmd = exec.Command("open", rawURL)
+	default:
+		cmd = exec.Command("xdg-open", rawURL)
+	}
+	return cmd.Run()
+}
+
+func copyToClipboard(text string) error {
+	var cmd *exec.Cmd
+	switch runtime.GOOS {
+	case "windows":
+		cmd = exec.Command("cmd", "/c", "clip")
+	case "darwin":
+		cmd = exec.Command("pbcopy")
+	default:
+		if _, err := exec.LookPath("xclip"); err == nil {
+			cmd = exec.Command("xclip", "-selection", "clipboard")
+		} else {
+			cmd = exec.Command("xsel", "--clipboard", "--input")
+		}
+	}
+	cmd.Stdin = strings.NewReader(text)
+	return cmd.Run()
+}
+
+func postFetchMenu(uri string) {
+	fmt.Fprint(os.Stderr, "\n  [O] Open in browser   [C] Copy to clipboard   [Enter] Exit\n  > ")
+	scanner := bufio.NewScanner(os.Stdin)
+	if !scanner.Scan() {
+		return
+	}
+	switch strings.ToLower(strings.TrimSpace(scanner.Text())) {
+	case "o":
+		if err := openInBrowser(uri); err != nil {
+			fmt.Fprintln(os.Stderr, "  Could not open browser:", err)
+		}
+	case "c":
+		if err := copyToClipboard(uri); err != nil {
+			fmt.Fprintln(os.Stderr, "  Could not copy to clipboard:", err)
+		} else {
+			fmt.Fprintln(os.Stderr, "  ✓ Copied to clipboard")
+		}
+	}
+}