Initial commit: Go driver for the Lian Li Galahad II LCD

Streams H.264 to the Galahad II LCD via USB (gousb) with:
- ffmpeg CLI transcoding (no fragile FFmpeg C-ABI bindings)
- pure-Go Annex-B access-unit splitting
- framerate pacing with graceful shutdown and USB reconnect
- TOML config, cobra CLI, structured slog logging, unit tests

internal/cli/list.go

@@ -0,0 +1,55 @@
+package cli
+
+import (
+	"fmt"
+	"sort"
+	"text/tabwriter"
+
+	"github.com/spf13/cobra"
+
+	"galahad2lcd/internal/device"
+)
+
+func newListCmd() *cobra.Command {
+	return &cobra.Command{
+		Use:   "list",
+		Short: "List USB devices visible to the driver",
+		Args:  cobra.NoArgs,
+		RunE: func(cmd *cobra.Command, _ []string) error {
+			ctx, stop := newSignalContext()
+			defer stop()
+
+			infos, err := device.ListDevices(ctx)
+			if err != nil {
+				return err
+			}
+
+			if len(infos) == 0 {
+				fmt.Fprintln(cmd.OutOrStdout(), "no USB devices found (are permissions configured?)")
+				return nil
+			}
+
+			sort.Slice(infos, func(i, j int) bool {
+				return infos[i].Bus < infos[j].Bus ||
+					(infos[i].Bus == infos[j].Bus && infos[i].Address < infos[j].Address)
+			})
+
+			w := tabwriter.NewWriter(cmd.OutOrStdout(), 0, 4, 2, ' ', 0)
+			fmt.Fprintln(w, "BUS\tADDR\tVID:PID\tPRODUCT\t")
+			for _, info := range infos {
+				product := info.Product
+				if product == "" {
+					product = "-"
+				}
+				marker := " "
+				if info.IsLCD {
+					marker = "*"
+				}
+				fmt.Fprintf(w, "%s%d\t%d\t%04x:%04x\t%s\t\n",
+					marker, info.Bus, info.Address, info.VendorID, info.ProductID, product)
+			}
+			fmt.Fprintln(w, "* Lian Li Galahad II LCD (0416:7395)")
+			return w.Flush()
+		},
+	}
+}