[next-wave] Wire frontend to live Runtime Guard Wrapper event stream

[Gbangbolaoluwagbemiga]

Context

The Runtime Guard Wrapper emits call events for every guarded function invocation. We need a dashboard page that subscribes to these events live and visualizes them.

Tasks

• New page: frontend/app/dashboard/page.tsx
• Subscribe to Soroban RPC getEvents for the wrapper contract
• Render a live-updating timeline of guarded calls (function_name, success, timestamp)
• Bar chart of calls per function (recharts or visx)
• Success/failure ratio gauge
• Manual 'Replay last 100 events' button
• Dark-mode-only design that matches existing branding (teal #2dd4bf accent)

Acceptance Criteria

• New events appear in the UI within 15 seconds of being recorded on-chain
• Page does not leak event subscriptions on unmount
• Mobile responsive (cards stack at <768px)