feat: add pitch-deck service to core infrastructure

Migrated pitch-deck from breakpilot-pwa to breakpilot-core.
Container: bp-core-pitch-deck on port 3012.

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

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

@@ -0,0 +1,30 @@
+import { NextRequest, NextResponse } from 'next/server'
+import pool from '@/lib/db'
+
+// PUT: Update a single assumption and trigger recompute
+export async function PUT(request: NextRequest) {
+  try {
+    const body = await request.json()
+    const { scenarioId, key, value } = body
+
+    if (!scenarioId || !key || value === undefined) {
+      return NextResponse.json({ error: 'scenarioId, key, and value are required' }, { status: 400 })
+    }
+
+    const client = await pool.connect()
+    try {
+      const jsonValue = JSON.stringify(value)
+      await client.query(
+        'UPDATE pitch_fm_assumptions SET value = $1 WHERE scenario_id = $2 AND key = $3',
+        [jsonValue, scenarioId, key]
+      )
+
+      return NextResponse.json({ success: true })
+    } finally {
+      client.release()
+    }
+  } catch (error) {
+    console.error('Update assumption error:', error)
+    return NextResponse.json({ error: 'Failed to update assumption' }, { status: 500 })
+  }
+}