fix(pgsql): handle default values for array types in migrations

* update default value quoting logic for PostgreSQL
* add tests for array default value handling

pkg/writers/pgsql/migration_writer_test.go

@@ -57,6 +57,46 @@ func TestWriteMigration_NewTable(t *testing.T) {
 	}
 }
 
+func TestWriteMigration_ArrayDefault(t *testing.T) {
+	current := models.InitDatabase("testdb")
+	currentSchema := models.InitSchema("public")
+	current.Schemas = append(current.Schemas, currentSchema)
+
+	model := models.InitDatabase("testdb")
+	modelSchema := models.InitSchema("public")
+
+	table := models.InitTable("plans", "public")
+
+	tagsCol := models.InitColumn("tags", "plans", "public")
+	tagsCol.Type = "text[]"
+	tagsCol.NotNull = true
+	tagsCol.Default = "''{}''"
+	table.Columns["tags"] = tagsCol
+
+	modelSchema.Tables = append(modelSchema.Tables, table)
+	model.Schemas = append(model.Schemas, modelSchema)
+
+	var buf bytes.Buffer
+	writer, err := NewMigrationWriter(&writers.WriterOptions{})
+	if err != nil {
+		t.Fatalf("Failed to create writer: %v", err)
+	}
+	writer.writer = &buf
+
+	err = writer.WriteMigration(model, current)
+	if err != nil {
+		t.Fatalf("WriteMigration failed: %v", err)
+	}
+
+	output := buf.String()
+	if !strings.Contains(output, "tags text[] DEFAULT '{}' NOT NULL") {
+		t.Fatalf("expected normalized array default in migration, got:\n%s", output)
+	}
+	if strings.Contains(output, "'''{}'''") {
+		t.Fatalf("migration still contains triple-quoted array default:\n%s", output)
+	}
+}
+
 func TestWriteMigration_WithAudit(t *testing.T) {
 	// Current database (empty)
 	current := models.InitDatabase("testdb")