Add contractors by residence endpoint and Bruno API collection

- Add GET /contractors/by-residence/:residence_id/ endpoint
- Create comprehensive Bruno API collection (89 endpoints)
- Collection covers all API endpoints with Local and Dev environments

🤖 Generated with [Claude Code](https://claude.com/claude-code)

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

internal/router/router.go

@@ -270,6 +270,7 @@ func setupContractorRoutes(api *gin.RouterGroup, contractorHandler *handlers.Con
 	{
 		contractors.GET("/", contractorHandler.ListContractors)
 		contractors.POST("/", contractorHandler.CreateContractor)
+		contractors.GET("/by-residence/:residence_id/", contractorHandler.ListContractorsByResidence)
 		contractors.GET("/:id/", contractorHandler.GetContractor)
 		contractors.PUT("/:id/", contractorHandler.UpdateContractor)
 		contractors.PATCH("/:id/", contractorHandler.UpdateContractor)