feat(server): implement switchable logging formats (console/json) (#24791)

* feat(server): add LogFormat enum and configuration

* feat(server): add structured logging formatters

* feat(server): implement switchable logging formats (console/json)

* Revert "feat(server): add LogFormat enum and configuration"

This reverts commit 565e95ae68.

* feat(server): implement JSON logging using NestJS native support

* refactor: rename LOG_FORMAT to IMMICH_LOG_FORMAT for consistency

* docs: add IMMICH_LOG_FORMAT documentation

* chore: format environment-variables.md

* chore: format monitoring.md

server/src/repositories/config.repository.ts

@@ -17,6 +17,7 @@ import {
   ImmichHeader,
   ImmichTelemetry,
   ImmichWorker,
+  LogFormat,
   LogLevel,
   QueueName,
 } from 'src/enum';
@@ -29,6 +30,7 @@ export interface EnvData {
   environment: ImmichEnvironment;
   configFile?: string;
   logLevel?: LogLevel;
+  logFormat?: LogFormat;
 
   buildMetadata: {
     build?: string;
@@ -233,6 +235,7 @@ const getEnv = (): EnvData => {
     environment,
     configFile: dto.IMMICH_CONFIG_FILE,
     logLevel: dto.IMMICH_LOG_LEVEL,
+    logFormat: dto.IMMICH_LOG_FORMAT || LogFormat.Console,
 
     buildMetadata: {
       build: dto.IMMICH_BUILD,