refactor: simplify KPI to 4 metrics and update CLAUDE.md (#83)

KPI page: removed operational grid (Intäktstillväxt, Kostnadsandel,
Snittbetaltid — all usually empty or redundant). Now shows 4 cards
(Resultat, Kassa, Kundfordringar, Moms) + trend chart. Removed unused
fields from KPIReport type and simplified API route.

CLAUDE.md: documented MCP server extension, API key infrastructure,
OAuth 2.1 flow, gnubok-mcp npm package, KPI page, cookieless Supabase
client, and updated migration count (65 → 70).

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

app/(dashboard)/kpi/page.tsx

@@ -4,7 +4,6 @@ import { useState, useEffect } from 'react'
 import { Label } from '@/components/ui/label'
 import { Card, CardContent } from '@/components/ui/card'
 import { KPIHeroCards } from '@/components/kpi/KPIHeroCards'
-import { KPIOperationalGrid } from '@/components/kpi/KPIOperationalGrid'
 import { KPITrendChart } from '@/components/kpi/KPITrendChart'
 import type { FiscalPeriod, KPIReport } from '@/types'
 
@@ -108,7 +107,6 @@ export default function KpiPage() {
       {!isLoadingReport && !error && report && (
         <>
           <KPIHeroCards report={report} />
-          <KPIOperationalGrid report={report} />
           {report.months.length > 0 && <KPITrendChart months={report.months} />}
         </>
       )}
@@ -138,16 +136,6 @@ function LoadingSkeleton() {
           </Card>
         ))}
       </div>
-      <div className="grid grid-cols-1 sm:grid-cols-2 gap-4">
-        {[1, 2, 3, 4].map((i) => (
-          <Card key={i}>
-            <CardContent className="p-5 space-y-2">
-              <div className="h-3 bg-muted rounded w-24 animate-pulse" />
-              <div className="h-6 bg-muted rounded w-20 animate-pulse" />
-            </CardContent>
-          </Card>
-        ))}
-      </div>
       <Card>
         <CardContent className="p-5 space-y-3">
           <div className="h-4 bg-muted rounded w-40 animate-pulse" />