feat: Add interactive analytics charts with volume and token breakdown

[Austinaminu2]

Description

The analytics page (/app/analytics) exists but lacks meaningful data visualizations. For a streaming protocol, users need to understand their streaming activity through charts and metrics.

Proposed Charts

1. Streaming Volume Over Time — area chart showing total tokens streamed per day/week/month
2. Token Distribution — donut chart breaking down streams by token (XLM, USDC, EURC)
3. Stream Status Breakdown — bar chart showing active vs completed vs cancelled streams
4. Top Recipients — table showing most-streamed-to addresses with totals
5. Unlock Progress — aggregate progress bar showing total unlocked vs locked across all streams

Technical Approach

Use recharts (already common in React ecosystems) or @visx/xys for lightweight, composable charts. Data derived from the existing useStreams hook — no new contract calls needed.

Acceptance Criteria

• At least 3 chart types rendered on the analytics page
• Charts update when new streams are created or status changes
• Date range selector (7d, 30d, 90d, all time)
• Empty states for users with no streams
• Charts render correctly in both light and dark themes
• Responsive layout — charts stack vertically on mobile