[Dashboard] KYC Rejection Details & Interactive Volume Chart

[G-ELM]

Summary

• KYC panel: Replaces the single generic rejection message in
  KycStatusView with a structured list of KycRejectionReason items.
  Each card shows a rejection code badge (high/medium severity),
  the affected field, a category icon (Document / Selfie / Address /
  Identity), a plain-language description, and a specific corrective
  action the user must take before resubmitting.

• Volume chart: Adds VolumeChart — a zero-dependency, vanilla SVG
  bar chart that replaces the "Volume Chart Placeholder" in
  DashboardOverview. Features include a 7D / 1M / 3M period selector,
  side-by-side deposit (indigo) and withdrawal (amber) bars per
  interval, Y-axis grid lines with auto-scaled labels, and an inline SVG
  tooltip that surfaces exact deposit/withdrawal values on column hover.

Files changed

• dashboard/src/components/KycStatusView.tsx — structured rejection
  reasons with severity badges and per-reason fix guidance
• dashboard/src/components/VolumeChart.tsx — new interactive SVG
  chart component
• dashboard/src/components/DashboardOverview.tsx — wires
  VolumeChart into the dashboard grid

Fixes #593
Fixes #596

[drips-wave]

@G-ELM Great news! 🎉 Based on an automated assessment of this PR, the linked Wave issue(s) no longer count against your application limits.

You can now already apply to more issues while waiting for a review of this PR. Keep up the great work! 🚀

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