chore: apply ESLint auto-fix across entire backend

Reformats code style (line breaks, indentation, type annotations)
without changing logic. Also includes minor feature additions bundled
in the same lint run (stats service, user-settings groups, agrarmonitor
polling improvements).

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

paperless-backend/src/auth/api-keys.service.ts

@@ -13,22 +13,27 @@ export class ApiKeysService {
     private readonly apiKeyRepo: Repository<ApiKey>,
   ) {}
 
-  async createApiKey(name: string, expiresDays?: number): Promise<{ plainKey: string; entity: ApiKey }> {
+  async createApiKey(
+    name: string,
+    expiresDays?: number,
+  ): Promise<{ plainKey: string; entity: ApiKey }> {
     const prefix = 'pm_';
     const randomPart = crypto.randomBytes(24).toString('hex'); // 48 chars hex
     const plainKey = `${prefix}${randomPart}`;
-    
+
     const keyHash = this.hashKey(plainKey);
-    
+
     const apiKey = this.apiKeyRepo.create({
       name,
       keyPrefix: prefix,
       keyHash,
-      expiresAt: expiresDays ? new Date(Date.now() + expiresDays * 24 * 60 * 60 * 1000) : null,
+      expiresAt: expiresDays
+        ? new Date(Date.now() + expiresDays * 24 * 60 * 60 * 1000)
+        : null,
     });
 
     const savedKey = await this.apiKeyRepo.save(apiKey);
-    
+
     return {
       plainKey,
       entity: savedKey,
@@ -37,7 +42,7 @@ export class ApiKeysService {
 
   async validateKey(plainKey: string): Promise<ApiKey> {
     const keyHash = this.hashKey(plainKey);
-    
+
     const apiKey = await this.apiKeyRepo.findOne({
       where: { keyHash },
     });
@@ -52,7 +57,11 @@ export class ApiKeysService {
 
     // Update last used timestamp (async, don't wait for it to return response faster)
     apiKey.lastUsedAt = new Date();
-    this.apiKeyRepo.save(apiKey).catch(err => this.logger.error('Fehler beim Aktualisieren von lastUsedAt', err));
+    this.apiKeyRepo
+      .save(apiKey)
+      .catch((err) =>
+        this.logger.error('Fehler beim Aktualisieren von lastUsedAt', err),
+      );
 
     return apiKey;
   }