revert admin password logging to slog.Info (closes #26)

internal/database/database.go

@@ -3,9 +3,7 @@ package database
 import (
 	"context"
 	"database/sql"
-	"fmt"
 	"log/slog"
-	"os"
 
 	"go.uber.org/fx"
 	"gorm.io/driver/sqlite"
@@ -120,17 +118,10 @@ func (d *Database) migrate() error {
 			return err
 		}
 
-		// Print the password directly to stderr so it never ends up in
-		// structured JSON log aggregation. This message is only shown
-		// once on first startup.
-		fmt.Fprintf(os.Stderr, "\n"+
-			"==========================================================\n"+
-			"  ADMIN USER CREATED\n"+
-			"  Username: admin\n"+
-			"  Password: %s\n"+
-			"  SAVE THIS PASSWORD — it will not be shown again!\n"+
-			"==========================================================\n\n",
-			password,
+		d.log.Info("admin user created",
+			"username", "admin",
+			"password", password,
+			"message", "SAVE THIS PASSWORD - it will not be shown again!",
 		)
 	}