Add UK Compliance Reports section to RetailShield dashboard

[TFT444]

Summary

Add a UK Compliance Reports section to frontend/src/RetailShield.jsx that automatically generates live compliance report cards when a CRITICAL incident is detected via the SIMULATE ATTACK flow.

Feature Requirements

Trigger

When SIMULATE ATTACK fires and a CRITICAL severity event is injected, a compliance report card is automatically generated in the new section.

UI Elements

1. Urgent header banner — Red "UK REGULATORY NOTIFICATION REQUIRED" bar when reports are active
2. Incident summary table — title, severity, detection time, MITRE technique, affected systems
3. Live countdown timers:
   • 24h NCSC early-warning (CSR Bill) — turns red when < 6h remaining
   • 72h ICO full report (UK GDPR Art.33) — turns amber when < 24h remaining
4. Pre-filled 7-section UK draft report (expandable):
   • §1 Incident Overview (auto-filled)
   • §2 Nature of the Breach (auto-filled based on MITRE tactic)
   • §3 Affected Data Categories & Volume (auto-filled)
   • §4 Likely Consequences (auto-filled)
   • §5 Measures Taken (auto-filled from playbook actions)
   • §6 Notification Timeline (auto-filled with deadlines)
   • §7 Data Controller Contact ([REVIEWER] placeholders)
5. Action buttons:
   • "Submit to ICO" — opens https://ico.org.uk/for-organisations/report-a-breach/ in new tab
   • "Submit to NCSC" — opens https://www.ncsc.gov.uk/section/about-this-website/incident-management in new tab
   • "Download Draft Report" — generates .txt file via URL.createObjectURL
6. Disclaimer banner — amber warning that human review is required before submission
7. Empty state — green "No reportable incidents" card when no active compliance reports

Design

• Match existing dark design system (C tokens: C.card, C.surface, C.border, C.red, C.orange, C.yellow, C.green, C.blue)
• No external CSS or new dependencies

Affected Files

• frontend/src/RetailShield.jsx — new state, modified runAttackSimulation, new ComplianceReportCard component, new section in JSX

Acceptance Criteria

• Section shows green "No reportable incidents" on load
• Clicking SIMULATE ATTACK generates 4 compliance report cards (one per CRITICAL event)
• Each card shows live countdown timers that decrement every second
• Countdowns change colour when approaching deadline (NCSC red < 6h, ICO amber < 24h)
• Expanding a card shows all 7 draft report sections
• §7 displays [REVIEWER] placeholders
• Download button saves a .txt file with the full 7-section report
• ICO and NCSC buttons open correct official URLs in a new tab
• Disclaimer banner visible on each expanded card
• Design matches existing dark theme