Enhance API documentation and restructure routes for improved clarity

- Updated README.md to include comprehensive Swagger documentation details, highlighting new features and endpoint categories.
- Introduced a new router structure to streamline route registration for admin and public endpoints, enhancing maintainability.
- Updated health check endpoint documentation to reflect comprehensive server status information.
- Enhanced customer and company management routes with improved descriptions and examples in Swagger.
- Refactored customer and user handlers to remove obsolete route registrations, aligning with the new router structure.
- Improved response handling in customer and user services to utilize string IDs consistently.
- Updated validation rules and forms for customer management to support multiple company assignments.
- Enhanced logging practices across services to ensure better traceability and error handling.

internal/customer/form.go

@@ -2,8 +2,10 @@ package customer
 
 // CreateCustomerForm represents the form for creating a new customer
 type CreateCustomerForm struct {
-	Type      string  `json:"type" valid:"required,in(individual|company|government)"`
-	CompanyID *string `json:"company_id,omitempty" valid:"optional,uuid"`
+	Type string `json:"type" valid:"required,in(individual|company|government)"`
+
+	// Company assignments
+	CompanyIDs []string `json:"company_ids,omitempty" valid:"optional"`
 
 	// Individual customer fields
 	FirstName *string `json:"first_name,omitempty" valid:"optional,length(2|50)"`
@@ -41,8 +43,10 @@ type CreateCustomerForm struct {
 
 // UpdateCustomerForm represents the form for updating a customer
 type UpdateCustomerForm struct {
-	Type      *string `json:"type,omitempty" valid:"optional,in(individual|company|government)"`
-	CompanyID *string `json:"company_id,omitempty" valid:"optional,uuid"`
+	Type *string `json:"type,omitempty" valid:"optional,in(individual|company|government)"`
+
+	// Company assignments
+	CompanyIDs []string `json:"company_ids,omitempty" valid:"optional"`
 
 	// Individual customer fields
 	FirstName *string `json:"first_name,omitempty" valid:"optional,length(2|50)"`
@@ -154,8 +158,10 @@ type CreateCustomerMobileForm struct {
 	Password  string  `json:"password" valid:"required,length(8|128)"`
 	Phone     *string `json:"phone,omitempty" valid:"optional,length(10|20)"`
 	Mobile    *string `json:"mobile,omitempty" valid:"optional,length(10|20)"`
-	CompanyID *string `json:"company_id,omitempty" valid:"optional,uuid"`
-	Industry  *string `json:"industry,omitempty" valid:"optional,length(2|100)"`
+
+	// Company assignments
+	CompanyIDs []string `json:"company_ids,omitempty" valid:"optional"`
+	Industry   *string  `json:"industry,omitempty" valid:"optional,length(2|100)"`
 }
 
 type UpdateCustomerMobileForm struct {
@@ -164,8 +170,10 @@ type UpdateCustomerMobileForm struct {
 	FullName  *string `json:"full_name,omitempty" valid:"optional,length(2|100)"`
 	Phone     *string `json:"phone,omitempty" valid:"optional,length(10|20)"`
 	Mobile    *string `json:"mobile,omitempty" valid:"optional,length(10|20)"`
-	CompanyID *string `json:"company_id,omitempty" valid:"optional,uuid"`
-	Industry  *string `json:"industry,omitempty" valid:"optional,length(2|100)"`
+
+	// Company assignments
+	CompanyIDs []string `json:"company_ids,omitempty" valid:"optional"`
+	Industry   *string  `json:"industry,omitempty" valid:"optional,length(2|100)"`
 }
 
 // Customer Authentication DTOs
@@ -204,3 +212,12 @@ type AuthResponse struct {
 	RefreshToken string            `json:"refresh_token"`
 	ExpiresAt    int64             `json:"expires_at"`
 }
+
+// Company assignment forms
+type AssignCompaniesForm struct {
+	CompanyIDs []string `json:"company_ids" valid:"required"`
+}
+
+type RemoveCompaniesForm struct {
+	CompanyIDs []string `json:"company_ids" valid:"required"`
+}