fix: add SnakeNamingStrategy for TypeORM to match snake_case DB columns

TypeORM entities use camelCase properties (tenantId, passwordHash) but
database tables use snake_case columns (tenant_id, password_hash). The
naming strategy automatically converts between the two conventions.

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

packages/shared/database/src/database.module.ts

@@ -2,6 +2,7 @@ import { DynamicModule, MiddlewareConsumer, Module, NestModule } from '@nestjs/c
 import { TypeOrmModule } from '@nestjs/typeorm';
 import { ConfigService } from '@nestjs/config';
 import { TenantContextMiddleware } from './tenant-context.middleware';
+import { SnakeNamingStrategy } from './snake-naming.strategy';
 
 @Module({})
 export class DatabaseModule implements NestModule {
@@ -25,6 +26,7 @@ export class DatabaseModule implements NestModule {
             autoLoadEntities: true,
             synchronize: config.get('NODE_ENV') === 'development',
             logging: config.get('DB_LOGGING', 'false') === 'true',
+            namingStrategy: new SnakeNamingStrategy(),
           }),
         }),
       ],

packages/shared/database/src/index.ts

@@ -2,3 +2,4 @@ export * from './tenant-aware.repository';
 export * from './database.module';
 export * from './tenant-provisioning.service';
 export * from './tenant-context.middleware';
+export * from './snake-naming.strategy';

packages/shared/database/src/snake-naming.strategy.ts

@@ -0,0 +1,28 @@
+import { DefaultNamingStrategy, NamingStrategyInterface } from 'typeorm';
+
+function toSnakeCase(str: string): string {
+  return str.replace(/([A-Z])/g, '_$1').toLowerCase().replace(/^_/, '');
+}
+
+export class SnakeNamingStrategy extends DefaultNamingStrategy implements NamingStrategyInterface {
+  tableName(className: string, customName: string): string {
+    return customName || toSnakeCase(className);
+  }
+
+  columnName(propertyName: string, customName: string, embeddedPrefixes: string[]): string {
+    const prefix = embeddedPrefixes.length ? toSnakeCase(embeddedPrefixes.join('_')) + '_' : '';
+    return prefix + (customName || toSnakeCase(propertyName));
+  }
+
+  relationName(propertyName: string): string {
+    return toSnakeCase(propertyName);
+  }
+
+  joinColumnName(relationName: string, referencedColumnName: string): string {
+    return toSnakeCase(relationName) + '_' + referencedColumnName;
+  }
+
+  joinTableColumnName(tableName: string, propertyName: string, columnName?: string): string {
+    return toSnakeCase(tableName) + '_' + (columnName || toSnakeCase(propertyName));
+  }
+}