feat: Phase 5+6 — Finanzplan Bridge + Financials-Slide Sync

- Adapter: fp_* Tabellen → FMResult Interface (60 Monate)
- Compute-Endpoint: source=finanzplan delegiert an Finanzplan-Engine
- useFinancialModel Hook: computeFromFinanzplan() + finanzplanResults
- FinancialsSlide: Toggle "Szenario-Modell" vs "Finanzplan (Excel)"
- Gruendungsdatum fix: EK+FK auf Aug (m8), Raumkosten ab Aug
- Startup-Preisstaffel: <10 MA ab 3.600 EUR/Jahr, 14-Tage-Test

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

pitch-deck/app/api/financial-model/compute/route.ts

@@ -1,10 +1,26 @@
 import { NextRequest, NextResponse } from 'next/server'
 import pool from '@/lib/db'
+import { computeFinanzplan } from '@/lib/finanzplan/engine'
+import { finanzplanToFMResults } from '@/lib/finanzplan/adapter'
 
 export async function POST(request: NextRequest) {
   try {
     const body = await request.json()
-    const { scenarioId } = body
+    const { scenarioId, source } = body
+
+    // If source=finanzplan, use the Finanzplan engine instead
+    if (source === 'finanzplan') {
+      try {
+        // First run the Finanzplan compute engine
+        await computeFinanzplan(pool, scenarioId || undefined)
+        // Then adapt results to FMResult format
+        const result = await finanzplanToFMResults(pool, scenarioId || undefined)
+        return NextResponse.json(result)
+      } catch (error) {
+        console.error('Finanzplan compute error:', error)
+        return NextResponse.json({ error: 'Finanzplan computation failed: ' + String(error) }, { status: 500 })
+      }
+    }
 
     if (!scenarioId) {
       return NextResponse.json({ error: 'scenarioId is required' }, { status: 400 })