fix: Produktions-Crash durch TypeORM-synchronize beheben

NODE_ENV=production deaktiviert synchronize (zerstörerischer ADD/DROP-COLUMN-
Churn auf MariaDB, der die 8126-Byte-Zeilengröße sprengte) und aktiviert
migrationsRun. Neue data-source.ts als einzige Konfigquelle (Laufzeit + CLI),
Migrations-Workflow (generate/run/revert) inkl. dotenv ergänzt.

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>

paperless-backend/src/database/data-source.ts

@@ -0,0 +1,81 @@
+import 'reflect-metadata';
+import { join } from 'path';
+import { config as loadEnv } from 'dotenv';
+import { DataSource, DataSourceOptions } from 'typeorm';
+import {
+  Client,
+  DocumentType,
+  DocumentField,
+  Task,
+  Postprocessing,
+  PostprocessingAction,
+  PostprocessingLog,
+  ExportTarget,
+  Setting,
+  Kontonummer,
+  Document,
+  UserClient,
+  Email,
+  Attachment,
+  Content,
+  ApiKey,
+  CorrespondentSetting,
+  BarcodeTemplate,
+  InboxDocument,
+  InboxPostprocessingAction,
+  CorrespondentEmailMapping,
+  UserSettings,
+  LabelPrintJob,
+} from './entities';
+
+// CLI-Kontext: .env laden (Laufzeit im Container liefert die Variablen via Docker,
+// dotenv ist dort ein No-Op). dotenv überschreibt bereits gesetzte Variablen nicht.
+loadEnv();
+loadEnv({ path: join(process.cwd(), '..', '.env') });
+
+export const entities = [
+  Client,
+  DocumentType,
+  DocumentField,
+  Task,
+  Postprocessing,
+  PostprocessingAction,
+  PostprocessingLog,
+  ExportTarget,
+  Setting,
+  Kontonummer,
+  Document,
+  UserClient,
+  Email,
+  Attachment,
+  Content,
+  ApiKey,
+  CorrespondentSetting,
+  BarcodeTemplate,
+  InboxDocument,
+  InboxPostprocessingAction,
+  CorrespondentEmailMapping,
+  UserSettings,
+  LabelPrintJob,
+];
+
+const isProduction = process.env.NODE_ENV === 'production';
+
+export const dataSourceOptions: DataSourceOptions = {
+  type: 'mysql',
+  host: process.env.DB_HOST ?? 'localhost',
+  port: Number(process.env.DB_PORT ?? 3306),
+  username: process.env.DB_USERNAME ?? 'root',
+  password: process.env.DB_PASSWORD ?? '',
+  database: process.env.DB_DATABASE ?? 'paperlessadd',
+  charset: 'utf8mb4',
+  entities,
+  migrations: [join(__dirname, 'migrations', '*.{ts,js}')],
+  // In Produktion: kein synchronize (zerstörerischer ALTER-Churn), Migrationen
+  // werden beim Start automatisch ausgeführt. In Dev: synchronize wie bisher.
+  synchronize: !isProduction,
+  migrationsRun: isProduction,
+};
+
+// Wird von der TypeORM-CLI verwendet (migration:generate / :run / :revert).
+export default new DataSource(dataSourceOptions);

paperless-backend/src/database/database.module.ts

@@ -1,75 +1,12 @@
 import { Module } from '@nestjs/common';
 import { TypeOrmModule } from '@nestjs/typeorm';
-import { ConfigModule, ConfigService } from '@nestjs/config';
-import {
-  Client,
-  DocumentType,
-  DocumentField,
-  Task,
-  Postprocessing,
-  PostprocessingAction,
-  PostprocessingLog,
-  ExportTarget,
-  Setting,
-  Kontonummer,
-  Document,
-  UserClient,
-  Email,
-  Attachment,
-  Content,
-  ApiKey,
-  CorrespondentSetting,
-  BarcodeTemplate,
-  InboxDocument,
-  InboxPostprocessingAction,
-  CorrespondentEmailMapping,
-  UserSettings,
-  LabelPrintJob,
-} from './entities';
-
-const entities = [
-  Client,
-  DocumentType,
-  DocumentField,
-  Task,
-  Postprocessing,
-  PostprocessingAction,
-  PostprocessingLog,
-  ExportTarget,
-  Setting,
-  Kontonummer,
-  Document,
-  UserClient,
-  Email,
-  Attachment,
-  Content,
-  ApiKey,
-  CorrespondentSetting,
-  BarcodeTemplate,
-  InboxDocument,
-  InboxPostprocessingAction,
-  CorrespondentEmailMapping,
-  UserSettings,
-  LabelPrintJob,
-];
+import { dataSourceOptions, entities } from './data-source';
 
 @Module({
   imports: [
-    TypeOrmModule.forRootAsync({
-      imports: [ConfigModule],
-      inject: [ConfigService],
-      useFactory: (config: ConfigService) => ({
-        type: 'mysql' as const,
-        host: config.get<string>('DB_HOST', 'localhost'),
-        port: config.get<number>('DB_PORT', 3306),
-        username: config.get<string>('DB_USERNAME', 'root'),
-        password: config.get<string>('DB_PASSWORD', ''),
-        database: config.get<string>('DB_DATABASE', 'paperlessadd'),
-        entities,
-        synchronize: config.get<string>('NODE_ENV') !== 'production',
-        charset: 'utf8mb4',
-      }),
-    }),
+    // Eine einzige Konfigurationsquelle (data-source.ts), geteilt zwischen
+    // NestJS-Laufzeit und TypeORM-CLI (Migrationen).
+    TypeOrmModule.forRoot(dataSourceOptions),
     TypeOrmModule.forFeature(entities),
   ],
   exports: [TypeOrmModule],