feat(ui): add relationship management features in schema editor

- Implement functionality to create, update, delete, and view relationships between tables.
- Introduce new UI screens for managing relationships, including forms for adding and editing relationships.
- Enhance table editor with navigation to relationship management.
- Ensure relationships are displayed in a structured table format for better usability.

pkg/ui/relation_dataops.go

@@ -0,0 +1,115 @@
+package ui
+
+import "git.warky.dev/wdevs/relspecgo/pkg/models"
+
+// Relationship data operations - business logic for relationship management
+
+// CreateRelationship creates a new relationship and adds it to a table
+func (se *SchemaEditor) CreateRelationship(schemaIndex, tableIndex int, rel *models.Relationship) *models.Relationship {
+	if schemaIndex < 0 || schemaIndex >= len(se.db.Schemas) {
+		return nil
+	}
+
+	schema := se.db.Schemas[schemaIndex]
+	if tableIndex < 0 || tableIndex >= len(schema.Tables) {
+		return nil
+	}
+
+	table := schema.Tables[tableIndex]
+	if table.Relationships == nil {
+		table.Relationships = make(map[string]*models.Relationship)
+	}
+
+	table.Relationships[rel.Name] = rel
+	table.UpdateDate()
+	return rel
+}
+
+// UpdateRelationship updates an existing relationship
+func (se *SchemaEditor) UpdateRelationship(schemaIndex, tableIndex int, oldName string, rel *models.Relationship) bool {
+	if schemaIndex < 0 || schemaIndex >= len(se.db.Schemas) {
+		return false
+	}
+
+	schema := se.db.Schemas[schemaIndex]
+	if tableIndex < 0 || tableIndex >= len(schema.Tables) {
+		return false
+	}
+
+	table := schema.Tables[tableIndex]
+	if table.Relationships == nil {
+		return false
+	}
+
+	// Delete old entry if name changed
+	if oldName != rel.Name {
+		delete(table.Relationships, oldName)
+	}
+
+	table.Relationships[rel.Name] = rel
+	table.UpdateDate()
+	return true
+}
+
+// DeleteRelationship removes a relationship from a table
+func (se *SchemaEditor) DeleteRelationship(schemaIndex, tableIndex int, relName string) bool {
+	if schemaIndex < 0 || schemaIndex >= len(se.db.Schemas) {
+		return false
+	}
+
+	schema := se.db.Schemas[schemaIndex]
+	if tableIndex < 0 || tableIndex >= len(schema.Tables) {
+		return false
+	}
+
+	table := schema.Tables[tableIndex]
+	if table.Relationships == nil {
+		return false
+	}
+
+	delete(table.Relationships, relName)
+	table.UpdateDate()
+	return true
+}
+
+// GetRelationship returns a relationship by name
+func (se *SchemaEditor) GetRelationship(schemaIndex, tableIndex int, relName string) *models.Relationship {
+	if schemaIndex < 0 || schemaIndex >= len(se.db.Schemas) {
+		return nil
+	}
+
+	schema := se.db.Schemas[schemaIndex]
+	if tableIndex < 0 || tableIndex >= len(schema.Tables) {
+		return nil
+	}
+
+	table := schema.Tables[tableIndex]
+	if table.Relationships == nil {
+		return nil
+	}
+
+	return table.Relationships[relName]
+}
+
+// GetRelationshipNames returns all relationship names for a table
+func (se *SchemaEditor) GetRelationshipNames(schemaIndex, tableIndex int) []string {
+	if schemaIndex < 0 || schemaIndex >= len(se.db.Schemas) {
+		return nil
+	}
+
+	schema := se.db.Schemas[schemaIndex]
+	if tableIndex < 0 || tableIndex >= len(schema.Tables) {
+		return nil
+	}
+
+	table := schema.Tables[tableIndex]
+	if table.Relationships == nil {
+		return nil
+	}
+
+	names := make([]string, 0, len(table.Relationships))
+	for name := range table.Relationships {
+		names = append(names, name)
+	}
+	return names
+}