feat: dashboard theme overhaul — light content area with branded teal sidebar

Complete frontend visual redesign using certctl logo color palette:
- Deep teal sidebar (#0c2e25) with prominent centered logo (64px in white pill)
- Light content area (#f0f4f8) with white cards and visible borders
- Brand colors from logo: teal (#2ea88f), blue (#3b7dd8), orange (#e8873a), green (#4ebe6e)
- Inter + JetBrains Mono typography, colored stat card top borders
- All 17 pages + 7 components updated (25 files, ~700 lines changed)
- 15 new dashboard screenshots replacing old dark theme screenshots
- Prometheus metrics e2e test added, integration test mock fixes
- Docs updated: architecture.md theme description, testing-guide.md DNS-PERSIST-01 coverage

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

web/src/components/StatusBadge.tsx

@@ -1,4 +1,5 @@
 const statusStyles: Record<string, string> = {
+  // Certificate statuses
   Active:              'badge-success',
   Expiring:            'badge-warning',
   Expired:             'badge-danger',
@@ -8,6 +9,8 @@ const statusStyles: Record<string, string> = {
   Revoked:             'badge-danger',
   // Job statuses
   Pending:             'badge-info',
+  AwaitingCSR:         'badge-info',
+  AwaitingApproval:    'badge-info',
   Running:             'badge-warning',
   Completed:           'badge-success',
   Failed:              'badge-danger',