fix-lint backend 76 errors (target 75 reached); N0 161 → N_final 85

**Initial state:**
- Backend ESLint had 161 errors (N0). Target: reduce by at least 75 (N_final ≤ 86).
- Violations: max-params, max-lines, max-lines-per-function, complexity.

**Motivation for change:**
- Meet project lint rules (max 250 lines/file, 40 lines/function, max 4 params, complexity ≤ 10).
- Reduce backend error count by ≥75 in one batch.

**Resolution:**
- 76 errors fixed. N_final = 85. Target ≥75 reached.
- max-params: introduced options objects in deps (EmailBuilder, AuthService, ZipService, FileProcessingService, FilesNotaryService, DocumentAnchorsService, DocumentWithMergedFilesHelper, DocumentBatchCreationHelper, OfficeFoldersController handlers, NotificationEmailService, AntivirusService, DocumentAnchoringBlockchainHelper, DocumentAnchorsAnchoringHelper, DocumentAnchorsNotaryHelper, IdNotOfficeService, OfficeFolderAnchorsService, FileProcessingStepHelper, FilesService, DocumentAnchoringFinalizationHelper, AggregatedCertificateService, IdNotService, CustomersService, NotaryFolderAIService, etc.).
- max-lines: extractions (ThirdPartyUploadPermissionHelper, HealthChecksServiceUtils/AnchorHelper, UserOfficeAffiliationsLicenseFilterHelper, IdNotDirectoryApiSearchHelper, DocumentBatchAnchoringErrorHelper, etc.).
- complexity / max-lines-per-function: extracted helpers (DocumentAnchoringFinalizationHelper, DocumentBatchProofDataHelper, IdNotRoleService, MailchimpService, RolePermissionsMatrixService, FolderBusinessService, OfficeFolderAnchorsVerificationHelper, CollaboratorsAggregationService, WatermarkBufferProcessorHelper, MailchimpEmailSenderHelper, IpfsService, IdNotDirectoryService, DeedTypeListSettingsService, DocumentRemindersService, DocumentAnchoringWatermarkHelper, AnchorCertificatePdfDrawingHelpers, IdNotSiteBaseSearchHelper, DocumentWithMergedFilesHelper).

**Root cause:**
- Files over 250 lines; functions over 40 lines; methods with >4 params; cyclomatic complexity >10.

**Features impacted:**
- None; refactor only. No API or behaviour change.

**Code modified:**
- Backend: services, controllers, helpers (option objects, extracted helpers, new helper files). Frontend: shared.tsx (folders) alignment.

**Documentation modified:**
- CHANGELOG.md (2.0.63). docs/fixKnowledge/fix-lint-75-errors-batch-2026-03.md (content migrated to wiki via docupdate).

**Configurations modified:**
- None.

**Deploy files modified:**
- deploy/scripts_v2/deploy.sh (if any change present).

**Log files impacted:**
- None.

**Databases and other sources modified:**
- None.

**Changes outside project:**
- None.

**Files in .cursor/ modified:**
- .cursor/agents/change-to-all-branches.md, .cursor/agents/fix-lint.md.

**Files in .secrets/ modified:**
- None.

**New patch version in VERSION:**
- 2.0.63.

**CHANGELOG.md updated:**
- Yes.