Add Starlink status lines for the physical gateway pane (closes #3) (#7)

Detection is a TCP connect to the dish endpoint bound to the physical
interface; once a dish answers, get_status is read every 5s and two
status lines render under the physical pane, red on disconnect or
alert. No dish: nothing drawn, no RPC. Minimal vendored proto bindings
for get_status only. Independent review passed (PR 7 comment 100012).

Model: opus-4-8 (implementation and review); model: claude-fable-5
(merge)

internal/starlink/starlink_test.go

@@ -0,0 +1,79 @@
+package starlink_test
+
+import (
+	"testing"
+	"time"
+
+	"git.eeqj.de/sneak/rtnetmon/internal/starlink"
+)
+
+func TestRender(t *testing.T) {
+	t.Parallel()
+
+	connected := starlink.Status{
+		State:          "CONNECTED",
+		Uptime:         3*24*time.Hour + 4*time.Hour + 12*time.Minute,
+		ObstructionPct: 0.1,
+		Alerts:         0,
+		PopPingMs:      34,
+		PopPingDropPct: 0.0,
+		DownlinkMbps:   145.3,
+		UplinkMbps:     12.1,
+	}
+
+	tests := []struct {
+		name      string
+		status    starlink.Status
+		wantLine1 string
+		wantLine2 string
+		wantAlert bool
+	}{
+		{
+			name:      "connected, no alert",
+			status:    connected,
+			wantLine1: "Starlink: CONNECTED  uptime 3d 4h 12m  obstruction 0.1%  alerts 0",
+			wantLine2: "  pop ping 34ms / drop 0.0%  down 145.3Mbps / up 12.1Mbps",
+			wantAlert: false,
+		},
+		{
+			name: "searching is an alert",
+			status: starlink.Status{
+				State:  "SEARCHING",
+				Uptime: 0,
+			},
+			wantLine1: "Starlink: SEARCHING  uptime 0d 0h 0m  obstruction 0.0%  alerts 0",
+			wantLine2: "  pop ping 0ms / drop 0.0%  down 0.0Mbps / up 0.0Mbps",
+			wantAlert: true,
+		},
+		{
+			name: "connected but alerts active",
+			status: starlink.Status{
+				State:  "CONNECTED",
+				Uptime: 90 * time.Minute,
+				Alerts: 2,
+			},
+			wantLine1: "Starlink: CONNECTED  uptime 0d 1h 30m  obstruction 0.0%  alerts 2",
+			wantLine2: "  pop ping 0ms / drop 0.0%  down 0.0Mbps / up 0.0Mbps",
+			wantAlert: true,
+		},
+	}
+
+	for _, tt := range tests {
+		t.Run(tt.name, func(t *testing.T) {
+			t.Parallel()
+
+			line1, line2, alert := starlink.Render(tt.status)
+			if line1 != tt.wantLine1 {
+				t.Errorf("line1 = %q, want %q", line1, tt.wantLine1)
+			}
+
+			if line2 != tt.wantLine2 {
+				t.Errorf("line2 = %q, want %q", line2, tt.wantLine2)
+			}
+
+			if alert != tt.wantAlert {
+				t.Errorf("alert = %v, want %v", alert, tt.wantAlert)
+			}
+		})
+	}
+}