Add stream analytics page with cumulative withdrawal and flow rate charts per stream

[Chuks-coderr]

Overview

Recipients and senders want to visualize how a stream has been consumed over time. A per-stream analytics page would show cumulative withdrawals and remaining balance as charts.

Problem

Stream data is presented as a snapshot (current claimable balance) with no historical context. Users cannot see the withdrawal pattern over time.

Proposed Solution

• Add an "Analytics" tab on the stream detail page
• Charts: cumulative withdrawals over time, remaining balance over time, flow rate history (for variable-rate streams)
• Data sourced from on-chain event history via the indexer client
• Charts support date range filtering

Acceptance Criteria

• Analytics tab on the stream detail page
• Cumulative withdrawal chart renders correctly
• Remaining balance chart renders correctly
• Date range filter works on both charts
• Empty state shown when no withdrawal history exists