fix(status): source column reflects real traffic + theme-aware tray menu

- api/status sources now carry recent_ok/recent_err (last 300s real gateway
  requests via Stats.SourceRecent) so a source actually serving traffic is
  never shown as down just because probe /models got rate-limited
- WebUI source status column repaints every 5s (no more frozen-at-first-
  render) with a manual refresh button; shows success rate + probe + cooldown
- tray menu status rows were enabled:false (GTK fixed light-grey, invisible
  on light themes) — now enabled with no-op click and nativeTheme listener
  rebuilds the menu on dark/light switches
- ignore local ops scripts (scripts/, machine-specific)

.gitignore

@@ -17,3 +17,6 @@ cmd/gui/*.log
 .pi-glla/
 .codegraph/
 /build/
+
+# local ops scripts (machine-specific, not for sharing)
+scripts/