Implement unified domains table with migration, repository, and projection

Co-authored-by: adlerhurst <27845747+adlerhurst@users.noreply.github.com>

internal/v2/domain/repository.go

@@ -0,0 +1,107 @@
+package domain
+
+import (
+	"context"
+	"time"
+
+	"github.com/zitadel/zitadel/internal/domain"
+	"github.com/zitadel/zitadel/internal/v2/database"
+)
+
+// Domain represents a unified domain that can belong to either an instance or an organization
+type Domain struct {
+	ID             string
+	InstanceID     string
+	OrganizationID *string                          // nil for instance domains
+	Domain         string
+	IsVerified     bool
+	IsPrimary      bool
+	ValidationType *domain.OrgDomainValidationType // nil for instance domains
+	CreatedAt      time.Time
+	UpdatedAt      time.Time
+	DeletedAt      *time.Time
+}
+
+// IsInstanceDomain returns true if this is an instance domain (OrganizationID is nil)
+func (d *Domain) IsInstanceDomain() bool {
+	return d.OrganizationID == nil
+}
+
+// IsOrganizationDomain returns true if this is an organization domain (OrganizationID is not nil)
+func (d *Domain) IsOrganizationDomain() bool {
+	return d.OrganizationID != nil
+}
+
+// DomainSearchCriteria defines the search criteria for domains
+type DomainSearchCriteria struct {
+	ID             *string
+	Domain         *string
+	InstanceID     *string
+	OrganizationID *string
+	IsVerified     *bool
+	IsPrimary      *bool
+}
+
+// DomainPagination defines pagination options for domain queries
+type DomainPagination struct {
+	Limit  uint32
+	Offset uint32
+	SortBy DomainSortField
+	Order  database.SortOrder
+}
+
+// DomainSortField defines the fields available for sorting domain results
+type DomainSortField int
+
+const (
+	DomainSortFieldCreatedAt DomainSortField = iota
+	DomainSortFieldUpdatedAt
+	DomainSortFieldDomain
+)
+
+// DomainList represents a paginated list of domains
+type DomainList struct {
+	Domains    []*Domain
+	TotalCount uint64
+}
+
+// InstanceDomainRepository defines the repository interface for instance domain operations
+type InstanceDomainRepository interface {
+	// Add creates a new instance domain (always verified)
+	Add(ctx context.Context, instanceID, domain string) (*Domain, error)
+	
+	// SetPrimary sets the primary domain for an instance
+	SetPrimary(ctx context.Context, instanceID, domain string) error
+	
+	// Remove soft deletes an instance domain
+	Remove(ctx context.Context, instanceID, domain string) error
+	
+	// Get returns a single instance domain matching the criteria
+	// Returns error if multiple domains are found
+	Get(ctx context.Context, criteria DomainSearchCriteria) (*Domain, error)
+	
+	// List returns a list of instance domains matching the criteria with pagination
+	List(ctx context.Context, criteria DomainSearchCriteria, pagination DomainPagination) (*DomainList, error)
+}
+
+// OrganizationDomainRepository defines the repository interface for organization domain operations
+type OrganizationDomainRepository interface {
+	// Add creates a new organization domain
+	Add(ctx context.Context, instanceID, organizationID, domain string, validationType domain.OrgDomainValidationType) (*Domain, error)
+	
+	// SetVerified marks an organization domain as verified
+	SetVerified(ctx context.Context, instanceID, organizationID, domain string) error
+	
+	// SetPrimary sets the primary domain for an organization
+	SetPrimary(ctx context.Context, instanceID, organizationID, domain string) error
+	
+	// Remove soft deletes an organization domain
+	Remove(ctx context.Context, instanceID, organizationID, domain string) error
+	
+	// Get returns a single organization domain matching the criteria
+	// Returns error if multiple domains are found
+	Get(ctx context.Context, criteria DomainSearchCriteria) (*Domain, error)
+	
+	// List returns a list of organization domains matching the criteria with pagination
+	List(ctx context.Context, criteria DomainSearchCriteria, pagination DomainPagination) (*DomainList, error)
+}