fix(deploy): isolate application from hosting owner credentials

scripts/prepare-standalone.mjs

@@ -5,3 +5,4 @@ mkdirSync('.next/standalone/scripts', { recursive: true });
 cpSync('scripts/start-production.sh', '.next/standalone/scripts/start-production.sh');
 cpSync('scripts/notdienst-alarm-worker.mjs', '.next/standalone/scripts/notdienst-alarm-worker.mjs');
 cpSync('scripts/runtime-database-url.mjs', '.next/standalone/scripts/runtime-database-url.mjs');
+cpSync('scripts/verify-runtime-isolation.mjs', '.next/standalone/scripts/verify-runtime-isolation.mjs');

scripts/start-production.sh

@@ -5,6 +5,7 @@ if [ -n "${APP_DATABASE_PASSWORD_FILE:-}" ]; then
   DATABASE_URL="$(node scripts/runtime-database-url.mjs)"
   export DATABASE_URL
 fi
+unset POSTGRES_PASSWORD PGADMIN_DEFAULT_PASSWORD APP_DATABASE_PASSWORD MIGRATION_DATABASE_URL
 # Schema changes are applied by the maintenance image before runtime startup.
 if [ -n "${NOTDIENST_JOB_SECRET:-}" ]; then
   node scripts/notdienst-alarm-worker.mjs &

scripts/verify-runtime-isolation.mjs

@@ -0,0 +1,23 @@
+import { readFileSync } from 'node:fs';
+import { PrismaClient } from '@prisma/client';
+let prisma;
+try {
+  const main = Object.fromEntries(readFileSync('/proc/1/environ', 'utf8').split('\0').filter(Boolean).map(line => {
+    const index = line.indexOf('='); return [line.slice(0, index), line.slice(index + 1)];
+  }));
+  for (const key of ['POSTGRES_PASSWORD', 'PGADMIN_DEFAULT_PASSWORD', 'APP_DATABASE_PASSWORD', 'MIGRATION_DATABASE_URL']) {
+    if (process.env[key] || main[key]) throw new Error('Administrative credential reached the app.');
+  }
+  // Configured global/legacy URLs must not expose an administrative login either.
+  if (process.env.DATABASE_URL) throw new Error('Hosting injected a legacy database URL.');
+  if (new URL(main.DATABASE_URL).username !== 'kita_runtime') throw new Error('Wrong application database role.');
+  prisma = new PrismaClient({ datasourceUrl: main.DATABASE_URL });
+  const [row] = await prisma.$queryRawUnsafe('SELECT current_user');
+  if (row.current_user !== 'kita_runtime') throw new Error('Wrong effective database role.');
+  console.log('Runtime isolation verified: no administrative credentials in container/app environment; current_user=kita_runtime.');
+} catch {
+  console.error('Runtime isolation verification failed. Credential values were not logged.');
+  process.exitCode = 1;
+} finally {
+  await prisma?.$disconnect();
+}