fix(tui): correct delete confirm labels, normalize help text

Delete confirmation dialog used wrong magic numbers for entity kind
mapping — maintenance windows showed as "alert", settings deletions
showed as "monitor". Now uses tab/section constants to match correctly.

Also: consistent [q/Esc] Back across all views, extract detailKeys(),
remove dead maxSections variable, add nodes empty state hint, use
models.Status constants in siteOrder, delete orphaned theme.png.

internal/tui/view_detail_inline.go

@@ -57,8 +57,7 @@ func (m Model) viewDetailTwoCol(site models.Site, hist monitor.SiteHistory, widt
 		b.WriteString(l + " " + divChar + " " + r + "\n")
 	}
 
-	keys := m.st.subtleStyle.Render("[h] History  [s] SLA  [e] Edit  [esc] Close")
-	b.WriteString("  " + keys + "\n")
+	b.WriteString("  " + m.detailKeys() + "\n")
 
 	return lipgloss.NewStyle().Width(width).MaxWidth(width).Render(b.String())
 }
@@ -293,12 +292,15 @@ func (m Model) viewDetailSingleCol(site models.Site, hist monitor.SiteHistory, w
 		b.WriteString("  " + m.st.subtleStyle.Render("30d") + " " + m.uptimeTimeline(m.detailDailyDays, timelineW) + "\n")
 	}
 
-	keys := m.st.subtleStyle.Render("[h] History  [s] SLA  [e] Edit  [esc] Close")
-	b.WriteString("  " + keys + "\n")
+	b.WriteString("  " + m.detailKeys() + "\n")
 
 	return lipgloss.NewStyle().Width(width).MaxWidth(width).Render(b.String())
 }
 
+func (m Model) detailKeys() string {
+	return m.st.subtleStyle.Render("[h] History  [s] SLA  [e] Edit  [q/Esc] Back")
+}
+
 func (m Model) fmtStatusWord(status string) string {
 	switch status {
 	case "DOWN":