Implements missing service for project-specific warehouse assignments:
- CRUD operations for project warehouse assignments
- Stock queries by project (fraccionamiento)
- Transfer between project warehouses with transaction support
- Project inventory summary with stock value calculations
- Integration with ERP Core inventory tables
Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>
- Remove meta wrapper from PaginatedResult returns in findWithFilters and findAll
- Return flat format with total, page, limit, totalPages at top level
- Align with base.service.ts interface definition
- Controllers already updated to access flat pagination structure
