feat(index): implement GIN index support for quoted text columns and enhance index column resolution

pkg/writers/pgsql/writer_test.go

@@ -124,6 +124,40 @@ func TestWriteDatabase_GinIndexOnTextArrayDoesNotUseTrigramOperatorClass(t *test
 	}
 }
 
+func TestWriteDatabase_GinIndexOnQuotedTextColumnUsesTrigramOperatorClass(t *testing.T) {
+	db := models.InitDatabase("testdb")
+	schema := models.InitSchema("public")
+
+	table := models.InitTable("agent_personas", "public")
+
+	nameCol := models.InitColumn("name", "agent_personas", "public")
+	nameCol.Type = "text"
+	table.Columns["name"] = nameCol
+
+	index := &models.Index{
+		Name:    "idx_agent_personas_name_gin",
+		Type:    "gin",
+		Columns: []string{`"name"`},
+	}
+	table.Indexes[index.Name] = index
+
+	schema.Tables = append(schema.Tables, table)
+	db.Schemas = append(db.Schemas, schema)
+
+	var buf bytes.Buffer
+	writer := NewWriter(&writers.WriterOptions{})
+	writer.writer = &buf
+
+	if err := writer.WriteDatabase(db); err != nil {
+		t.Fatalf("WriteDatabase failed: %v", err)
+	}
+
+	output := buf.String()
+	if !strings.Contains(output, `USING gin (name gin_trgm_ops)`) {
+		t.Fatalf("expected quoted text GIN index to include gin_trgm_ops, got:\n%s", output)
+	}
+}
+
 func TestWriteForeignKeys(t *testing.T) {
 	// Create a test database with two related tables
 	db := models.InitDatabase("testdb")