perf(ui): stop update badge pulse ticker when hidden (Fluid F7)

[ZhuchkaTriplesix]

Parent

Part of #356 · Fluid perf audit F7 (P1)

Problem

UpdateAvailableBadge starts AnimationController..repeat() in initState even when showBadge is false and the build returns SizedBox.shrink — perpetual vsync work.

Where: lib/features/updater/update_available_badge.dart

Expected

• Start pulse only when badge visible; stop when hidden
• Honor Motion Off / reduced (no pulse or instant)
• Prefer QueryaMotion tokens over bare 1400ms (ties to F9)

Acceptance

• No repeating ticker while badge hidden
• Widget test for show/hide lifecycle
• Reduced/Off motion respected

Related

• F9 magic durations

[ZhuchkaTriplesix]

Fixed and merged on dev via Fluid perf PRs.