Show healed faults in dashboard (fault history)

[mfaferek93]

Bug

The web UI only fetches active faults (default ?status = pending + confirmed). Once a fault heals (PREPASSED → HEALED), it disappears from the dashboard entirely. There's no way to see fault history.

Context

Depends on selfpatch/ros2_medkit#217 — the gateway currently doesn't return HEALED/PREPASSED faults even with ?status=all. Once that's fixed, the web UI needs to use it.

Expected Behavior

• Dashboard should show healed faults (grayed out or with "healed" badge)
• Default view: active faults only (current behavior — correct)
• Toggle or tab to show "all faults" or "fault history" including healed
• Healed faults should show occurrence_count, first_occurred, last_occurred, healing timestamp

Acceptance Criteria

1. Fetch faults with ?status=all when history view is active
2. Visual distinction between active (CONFIRMED) and healed (HEALED) faults
3. Default view unchanged — only active faults
4. Healed fault cards show full lifecycle metadata