feat: add logging and migration runner skeleton

Wire a structured logger and a top-level migration job that drives extract, transform and load stages.

cmd/go_migrate/log.go

@@ -0,0 +1,15 @@
+package main
+
+import (
+	"time"
+
+	log "github.com/sirupsen/logrus"
+)
+
+func configureLog() {
+	log.SetFormatter(&log.TextFormatter{
+		FullTimestamp:   true,
+		TimestampFormat: time.StampMilli,
+	})
+	log.SetLevel(log.DebugLevel)
+}