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/monitor/monitor.go

@@ -19,6 +19,8 @@ import (
 	"time"
 
 	tcell "github.com/gdamore/tcell/v2"
+
+	"git.eeqj.de/sneak/rtnetmon/internal/starlink"
 )
 
 // Meter glyphs used to render the ASCII loss meter.
@@ -90,6 +92,12 @@ type Monitor struct {
 	// Interfaces to monitor (one or two)
 	interfaces []*InterfaceStatus
 
+	// Starlink status for the physical (non-VPN gateway) pane. All three
+	// are nil unless EnableStarlink was called for a monitored interface.
+	slClient starlink.Client
+	slState  *starlinkState
+	slPane   *InterfaceStatus
+
 	// Logging
 	logFile string
 
@@ -208,6 +216,8 @@ func (m *Monitor) Run(ctx context.Context) error {
 		go m.tcpLoop(ctx, st, tcpHosts)
 	}
 
+	go m.starlinkLoop(ctx)
+
 	m.logf("Starting UI loop")
 	m.uiLoop(ctx)
 	m.logf("UI loop exited, monitor ending")