feat(bunker): add QR code generation for bunker URI

- Add `--qrcode` flag to display a QR code for the bunker URI.
- Update `README.md` with usage instructions for the new flag.
- Include `qrterminal` dependency for QR code generation.

bunker.go

@@ -17,6 +17,7 @@ import (
 	"fiatjaf.com/nostr/nip19"
 	"fiatjaf.com/nostr/nip46"
 	"github.com/fatih/color"
+	"github.com/mdp/qrterminal/v3"
 	"github.com/urfave/cli/v3"
 )
 
@@ -65,6 +66,10 @@ var bunker = &cli.Command{
 			Usage:  "relays to connect to (can also be provided as naked arguments)",
 			Hidden: true,
 		},
+		&cli.BoolFlag{
+			Name:  "qrcode",
+			Usage: "display a QR code for the bunker URI",
+		},
 	},
 	Action: func(ctx context.Context, c *cli.Command) error {
 		// read config from file
@@ -293,6 +298,13 @@ var bunker = &cli.Command{
 					colors.bold(bunkerURI),
 				)
 			}
+
+			// Print QR code if requested
+			if c.Bool("qrcode") {
+				log("QR Code for bunker URI:\n")
+				qrterminal.Generate(bunkerURI, qrterminal.L, os.Stdout)
+				log("\n\n")
+			}
 		}
 		printBunkerInfo()