feat(pitch-deck): admin UI for investor + financial-model management (#3)

Adds /pitch-admin dashboard with real bcrypt admin accounts and full
audit attribution for every state-changing action.

- pitch_admins + pitch_admin_sessions tables (migration 002)
- pitch_audit_logs.admin_id + target_investor_id columns
- lib/admin-auth.ts: bcryptjs, single-session, jose JWT with audience claim
- middleware.ts: two-cookie gating with bearer-secret CLI fallback
- 14 new API routes (admin-auth, dashboard, investor detail/edit/resend,
  admins CRUD, fm scenarios + assumptions PATCH)
- 9 admin pages: login, dashboard, investors list/new/[id], audit,
  financial-model list/[id], admins
- Bootstrap CLI: npm run admin:create
- 36 vitest tests covering auth, admin-auth, rate-limit primitives

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

pitch-deck/components/pitch-admin/StatCard.tsx

@@ -0,0 +1,33 @@
+import { LucideIcon } from 'lucide-react'
+
+interface StatCardProps {
+  label: string
+  value: string | number
+  icon?: LucideIcon
+  hint?: string
+  accent?: 'indigo' | 'green' | 'amber' | 'rose'
+}
+
+const ACCENTS = {
+  indigo: 'text-indigo-400 bg-indigo-500/10 border-indigo-500/20',
+  green: 'text-green-400 bg-green-500/10 border-green-500/20',
+  amber: 'text-amber-400 bg-amber-500/10 border-amber-500/20',
+  rose: 'text-rose-400 bg-rose-500/10 border-rose-500/20',
+}
+
+export default function StatCard({ label, value, icon: Icon, hint, accent = 'indigo' }: StatCardProps) {
+  return (
+    <div className="bg-white/[0.04] border border-white/[0.06] rounded-2xl p-5">
+      <div className="flex items-start justify-between mb-3">
+        <span className="text-xs font-medium text-white/50 uppercase tracking-wider">{label}</span>
+        {Icon && (
+          <div className={`w-9 h-9 rounded-lg flex items-center justify-center border ${ACCENTS[accent]}`}>
+            <Icon className="w-4 h-4" />
+          </div>
+        )}
+      </div>
+      <div className="text-3xl font-semibold text-white">{value}</div>
+      {hint && <div className="text-xs text-white/40 mt-1">{hint}</div>}
+    </div>
+  )
+}