Enhance embedded Postgres configuration and logging setup

Added customizable startup parameters and log directory support for embedded Postgres. Introduced runtime configuration checks and warnings for required restarts when settings change to improve usability and debugging.

Author: derkan

config.go

@@ -15,6 +15,7 @@ type Config struct {
 	port                uint32
 	useUnixSocket       bool
 	unixSocketDirectory string
+	logDirectory        string
 	database            string
 	username            string
 	password            string
@@ -84,6 +85,13 @@ func (c Config) WithUnixSocketDirectory(dir string) Config {
 	return c
 }
 
+// LogDirectory sets the directory where the temporary embedded Postgres capture
+// file is created before its content is forwarded to the configured logger.
+func (c Config) LogDirectory(dir string) Config {
+	c.logDirectory = dir
+	return c
+}
+
 // Database sets the database name that will be created.
 func (c Config) Database(database string) Config {
 	c.database = database

embedded_postgres.go

@@ -77,7 +77,7 @@ func (ep *EmbeddedPostgres) Start() error {
 		}
 	}
 
-	logger, err := newSyncedLogger("", ep.config.logger)
+	logger, err := newSyncedLogger(ep.config.logDirectory, ep.config.logger)
 	if err != nil {
 		return errors.New("unable to create logger")
 	}

logging.go

@@ -15,6 +15,11 @@ type syncedLogger struct {
 }
 
 func newSyncedLogger(dir string, logger io.Writer) (*syncedLogger, error) {
+	if dir != "" {
+		if err := os.MkdirAll(dir, 0o755); err != nil {
+			return nil, err
+		}
+	}
 	file, err := os.CreateTemp(dir, "embedded_postgres_log")
 	if err != nil {
 		return nil, err