feat(writer): 🎉 Enhance PostgreSQL writer, fixed bugs found using origin

pkg/readers/dbml/reader.go

@@ -587,10 +587,10 @@ func (r *Reader) parseColumn(line, tableName, schemaName string) (*models.Column
 					refOp := strings.TrimSpace(refStr)
 					var isReverse bool
 					if strings.HasPrefix(refOp, "<") {
-						isReverse = column.IsPrimaryKey // < on PK means "is referenced by" (reverse)
-					} else if strings.HasPrefix(refOp, ">") {
-						isReverse = !column.IsPrimaryKey // > on FK means reverse
+						// < means "is referenced by" - only makes sense on PK columns
+						isReverse = column.IsPrimaryKey
 					}
+					// > means "references" - always a forward FK, never reverse
 
 					constraint = r.parseRef(refStr)
 					if constraint != nil {

pkg/readers/pgsql/reader.go

@@ -329,10 +329,10 @@ func (r *Reader) deriveRelationship(table *models.Table, fk *models.Constraint)
 	relationshipName := fmt.Sprintf("%s_to_%s", table.Name, fk.ReferencedTable)
 
 	relationship := models.InitRelationship(relationshipName, models.OneToMany)
-	relationship.FromTable = fk.ReferencedTable
-	relationship.FromSchema = fk.ReferencedSchema
-	relationship.ToTable = table.Name
-	relationship.ToSchema = table.Schema
+	relationship.FromTable = table.Name
+	relationship.FromSchema = table.Schema
+	relationship.ToTable = fk.ReferencedTable
+	relationship.ToSchema = fk.ReferencedSchema
 	relationship.ForeignKey = fk.Name
 
 	// Store constraint actions in properties

pkg/readers/pgsql/reader_test.go

@@ -328,12 +328,12 @@ func TestDeriveRelationship(t *testing.T) {
 		t.Errorf("Expected relationship type %s, got %s", models.OneToMany, rel.Type)
 	}
 
-	if rel.FromTable != "users" {
-		t.Errorf("Expected FromTable 'users', got '%s'", rel.FromTable)
+	if rel.FromTable != "orders" {
+		t.Errorf("Expected FromTable 'orders', got '%s'", rel.FromTable)
 	}
 
-	if rel.ToTable != "orders" {
-		t.Errorf("Expected ToTable 'orders', got '%s'", rel.ToTable)
+	if rel.ToTable != "users" {
+		t.Errorf("Expected ToTable 'users', got '%s'", rel.ToTable)
 	}
 
 	if rel.ForeignKey != "fk_orders_user_id" {