type safety enhancement

[feyishola]

closes #42

Completed Tasks:
✅ TypeScript Configuration Enhancement
Enabled strict type checking in tsconfig.json
Added comprehensive strict mode settings including:
strictNullChecks: true
noImplicitAny: true
strictBindCallApply: true
forceConsistentCasingInFileNames: true
And many other strict type checking options
✅ Comprehensive Type Definitions Created
Created src/types/ directory with modular type files:
prisma.types.ts - Prisma model interfaces and query types
service.types.ts - Service response and operation interfaces
validation.types.ts - Validation schemas and constraint types
security.types.ts - Authentication, MFA, and security interfaces
api.types.ts - API request/response and documentation types
guards.ts - Runtime type guards and assertion functions
✅ Service-Level Type Improvements
Valuation Service: Replaced 'any' types with proper interfaces, fixed error handling
Property Service: Added proper Prisma model typing, fixed error handling
Auth Service: Added authentication-specific types, improved error handling
API Key Service: Added API key management types
Document Service: Already had good typing, minimal changes needed
✅ DTO Validation Enhancement
Created comprehensive validation utilities in src/common/validators/validation.utils.ts
Added custom validation decorators for common use cases
Enhanced existing DTOs with proper validation constraints
✅ Type Guards and Runtime Safety
Implemented comprehensive type guard utilities
Added assertion functions for runtime type checking
Created type narrowing utilities for safe type conversion
✅ Prisma Type Enhancement
Created type-safe Prisma query builders
Added pagination and bulk operation utilities
Implemented Prisma error handling utilities
✅ Documentation Improvements
Added comprehensive JSDoc comments to type definitions
Created clear module documentation with usage examples
Added proper type documentation throughout
✅ Test File Improvements
Removed 'any' type assertions from test files
Improved test typing consistency
Fixed validation test cases

[LaGodxy]

@feyishola please fix the CI

[feyishola]

@LaGodxy fixed