issues-tui: wide, short terminal dashboard for current issues

Standalone cmd that runs the same pipeline as the webhook notifications
(alerts.LoadErrorEvents -> alerts.DetectAlerts -> cooldown suppressor) on
a schedule and renders what is firing as a row of severity-colored cards -
built for an ultra-wide, low display. A pattern shows PAGED when the scan
would have notified and ongoing while suppressed; disappearing spikes are
reported as recovered. -once prints one snapshot for cron/pipe use.
Colors follow the otel-ui design-system tokens (dark and light).

cmd/issues-tui/tui.go

@@ -0,0 +1,95 @@
+package main
+
+import (
+	"context"
+	"time"
+
+	tea "github.com/charmbracelet/bubbletea"
+)
+
+// modelConfig is the static configuration the dashboard needs beyond the
+// scanner.
+type modelConfig struct {
+	Interval time.Duration
+	Title    string
+	BaseURL  string
+}
+
+// tickMsg drives the clock and the scan countdown.
+type tickMsg time.Time
+
+// snapshotMsg carries a finished scan back into the model.
+type snapshotMsg snapshot
+
+type model struct {
+	sc   *scanner
+	cfg  modelConfig
+	snap snapshot
+
+	scanning   bool
+	nextScanAt time.Time
+
+	width, height int
+	ready         bool
+}
+
+func newModel(sc *scanner, cfg modelConfig) model {
+	return model{sc: sc, cfg: cfg, nextScanAt: time.Now()}
+}
+
+func (m model) Init() tea.Cmd {
+	return tea.Batch(tickClock(), m.scanCmd())
+}
+
+func tickClock() tea.Cmd {
+	return tea.Tick(time.Second, func(t time.Time) tea.Msg { return tickMsg(t) })
+}
+
+func (m *model) scanCmd() tea.Cmd {
+	sc := m.sc
+	return func() tea.Msg { return snapshotMsg(sc.Scan(context.Background(), time.Now())) }
+}
+
+func (m model) Update(msg tea.Msg) (tea.Model, tea.Cmd) {
+	switch msg := msg.(type) {
+	case tea.WindowSizeMsg:
+		m.width, m.height, m.ready = msg.Width, msg.Height, true
+		return m, nil
+
+	case tea.KeyMsg:
+		switch msg.String() {
+		case "q", "esc", "ctrl+c":
+			return m, tea.Quit
+		case "r":
+			if !m.scanning {
+				m.scanning = true
+				return m, m.scanCmd()
+			}
+			return m, nil
+		}
+		return m, nil
+
+	case tickMsg:
+		now := time.Time(msg)
+		cmd := tickClock()
+		if !m.scanning && !now.Before(m.nextScanAt) {
+			m.scanning = true
+			return m, tea.Batch(cmd, m.scanCmd())
+		}
+		return m, cmd
+
+	case snapshotMsg:
+		m.snap = snapshot(msg)
+		m.scanning = false
+		m.nextScanAt = time.Now().Add(m.cfg.Interval)
+		return m, nil
+	}
+	return m, nil
+}
+
+func (m model) View() string {
+	return renderSnapshot(m.snap, snapshotOptions{
+		Width: m.width, Height: m.height, Title: m.cfg.Title, BaseURL: m.cfg.BaseURL,
+		Scanning: m.scanning, NextScanAt: m.nextScanAt, Now: time.Now(),
+	})
+}