fix(writers): drop version stamps from generated output

Generated files carried the RelSpec version and build date, so every
rebuild produced a diff even when the schema was unchanged.

- bun, gorm, drizzle: remove the GeneratedBy template field and line
- pgsql, mssql, sqlite: emit a constant "-- Generated by RelSpec"
- bun: replace the version header test with a version-free assertion

pkg/buildinfo is unchanged and still backs the CLI version.

pkg/writers/pgsql/migration_writer.go

@@ -7,7 +7,6 @@ import (
 	"sort"
 	"strings"
 
-	"git.warky.dev/wdevs/relspecgo/pkg/buildinfo"
 	"git.warky.dev/wdevs/relspecgo/pkg/models"
 	"git.warky.dev/wdevs/relspecgo/pkg/pgsql"
 	"git.warky.dev/wdevs/relspecgo/pkg/writers"
@@ -144,7 +143,7 @@ func (w *MigrationWriter) WriteMigration(model, current *models.Database) error
 
 	// Write header
 	fmt.Fprintf(w.writer, "-- PostgreSQL Migration Script\n")
-	fmt.Fprintf(w.writer, "-- Generated by %s\n", buildinfo.GeneratedComment())
+	fmt.Fprintf(w.writer, "-- Generated by RelSpec\n")
 	fmt.Fprintf(w.writer, "-- Source: %s -> %s\n", current.Name, model.Name)
 	if w.options.ContinueOnError {
 		fmt.Fprintf(w.writer, "\\set ON_ERROR_STOP off\n")

pkg/writers/pgsql/writer.go

@@ -12,7 +12,6 @@ import (
 	"sync"
 	"time"
 
-	"git.warky.dev/wdevs/relspecgo/pkg/buildinfo"
 	"git.warky.dev/wdevs/relspecgo/pkg/models"
 	"git.warky.dev/wdevs/relspecgo/pkg/pgsql"
 	"git.warky.dev/wdevs/relspecgo/pkg/writers"
@@ -102,7 +101,7 @@ func (w *Writer) WriteDatabase(db *models.Database) error {
 	// Write header comment
 	fmt.Fprintf(w.writer, "-- PostgreSQL Database Schema\n")
 	fmt.Fprintf(w.writer, "-- Database: %s\n", db.Name)
-	fmt.Fprintf(w.writer, "-- Generated by %s\n", buildinfo.GeneratedComment())
+	fmt.Fprintf(w.writer, "-- Generated by RelSpec\n")
 	if w.options.ContinueOnError {
 		fmt.Fprintf(w.writer, "\\set ON_ERROR_STOP off\n")
 	}
@@ -126,7 +125,7 @@ func (w *Writer) GenerateDatabaseStatements(db *models.Database) ([]string, erro
 	// Add header comment
 	statements = append(statements, "-- PostgreSQL Database Schema")
 	statements = append(statements, fmt.Sprintf("-- Database: %s", db.Name))
-	statements = append(statements, "-- Generated by "+buildinfo.GeneratedComment())
+	statements = append(statements, "-- Generated by RelSpec")
 
 	// Process each schema in the database
 	for _, schema := range db.Schemas {
@@ -570,7 +569,7 @@ func (w *Writer) GenerateAddColumnsForDatabase(db *models.Database) ([]string, e
 
 	statements = append(statements, "-- Add missing columns to existing tables")
 	statements = append(statements, fmt.Sprintf("-- Database: %s", db.Name))
-	statements = append(statements, "-- Generated by "+buildinfo.GeneratedComment())
+	statements = append(statements, "-- Generated by RelSpec")
 
 	for _, schema := range db.Schemas {
 		schemaStatements, err := w.GenerateAddColumnStatements(schema)