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/starlink_test.go

@@ -0,0 +1,141 @@
+package monitor_test
+
+import (
+	"context"
+	"sync"
+	"testing"
+	"time"
+
+	"git.eeqj.de/sneak/rtnetmon/internal/monitor"
+	"git.eeqj.de/sneak/rtnetmon/internal/starlink"
+)
+
+// fakeDish is a Starlink client for tests: no dish, no network. It records
+// how often each method is called and returns programmed results.
+type fakeDish struct {
+	mu          sync.Mutex
+	probeOK     bool
+	status      starlink.Status
+	statusErr   error
+	probeCalls  int
+	statusCalls int
+}
+
+func (f *fakeDish) Probe(_ context.Context) bool {
+	f.mu.Lock()
+	defer f.mu.Unlock()
+
+	f.probeCalls++
+
+	return f.probeOK
+}
+
+func (f *fakeDish) Status(_ context.Context) (starlink.Status, error) {
+	f.mu.Lock()
+	defer f.mu.Unlock()
+
+	f.statusCalls++
+
+	return f.status, f.statusErr
+}
+
+func (f *fakeDish) counts() (int, int) {
+	f.mu.Lock()
+	defer f.mu.Unlock()
+
+	return f.probeCalls, f.statusCalls
+}
+
+func newTwoPaneMonitor() *monitor.Monitor {
+	return monitor.NewMonitor([]monitor.IfaceSpec{
+		{Name: ifaceTest0, Label: "A"},
+		{Name: ifaceTest1, Label: "B"},
+	}, "")
+}
+
+func TestEnableStarlinkSelectsPane(t *testing.T) {
+	t.Parallel()
+
+	mon := newTwoPaneMonitor()
+	mon.EnableStarlink(ifaceTest1)
+
+	if !mon.StarlinkEnabled() {
+		t.Fatal("StarlinkEnabled = false, want true")
+	}
+
+	if got := mon.StarlinkPaneName(); got != ifaceTest1 {
+		t.Errorf("StarlinkPaneName = %q, want %q", got, ifaceTest1)
+	}
+}
+
+func TestEnableStarlinkUnknownInterface(t *testing.T) {
+	t.Parallel()
+
+	mon := newTwoPaneMonitor()
+	mon.EnableStarlink("does-not-exist")
+
+	if mon.StarlinkEnabled() {
+		t.Error("StarlinkEnabled = true for an unknown interface, want false")
+	}
+}
+
+// TestStarlinkNoDishNoStatus verifies that when no dish answers, no status
+// is ever fetched and nothing is marked detected.
+func TestStarlinkNoDishNoStatus(t *testing.T) {
+	t.Parallel()
+
+	mon := newTwoPaneMonitor()
+	fake := &fakeDish{probeOK: false}
+	mon.SetStarlinkClient(ifaceTest1, fake)
+
+	ctx := context.Background()
+	mon.StarlinkProbeStep(ctx)
+	mon.StarlinkRefreshStep(ctx)
+
+	detected, haveStatus, _ := mon.StarlinkSnapshot()
+	if detected || haveStatus {
+		t.Errorf("detected=%v haveStatus=%v, want both false", detected, haveStatus)
+	}
+
+	if _, status := fake.counts(); status != 0 {
+		t.Errorf("status calls = %d, want 0 (no probing noise)", status)
+	}
+}
+
+// TestStarlinkDetectedFetchesStatus verifies that once a dish answers,
+// detection triggers a status fetch and later refreshes fetch again.
+func TestStarlinkDetectedFetchesStatus(t *testing.T) {
+	t.Parallel()
+
+	mon := newTwoPaneMonitor()
+	want := starlink.Status{
+		State:        "CONNECTED",
+		Uptime:       2 * time.Hour,
+		DownlinkMbps: 100,
+	}
+	fake := &fakeDish{probeOK: true, status: want}
+	mon.SetStarlinkClient(ifaceTest1, fake)
+
+	ctx := context.Background()
+	mon.StarlinkProbeStep(ctx)
+
+	detected, haveStatus, got := mon.StarlinkSnapshot()
+	if !detected || !haveStatus {
+		t.Fatalf("detected=%v haveStatus=%v, want both true", detected, haveStatus)
+	}
+
+	if got != want {
+		t.Errorf("status = %+v, want %+v", got, want)
+	}
+
+	mon.StarlinkRefreshStep(ctx)
+
+	probe, status := fake.counts()
+	if probe != 1 {
+		t.Errorf("probe calls = %d, want 1", probe)
+	}
+
+	if status != 2 {
+		t.Errorf("status calls = %d, want 2", status)
+	}
+}