Fix password setting and inhibit system sleep during install

iridium_installer/backend/os_install.py

@@ -237,8 +237,19 @@ UUID={efi_uuid} /boot vfat defaults 0 2
             run_command(["chroot", mount_root, "useradd", "-m", "-G", "wheel", user_info["username"]])
             
             # Set password
-            p = subprocess.Popen(["chroot", mount_root, "chpasswd"], stdin=subprocess.PIPE, text=True)
-            p.communicate(input=f"{user_info['username']}:{user_info['password']}")
+            try:
+                logger.info("Setting user password...")
+                p = subprocess.run(
+                    ["chroot", mount_root, "chpasswd"],
+                    input=f"{user_info['username']}:{user_info['password']}\n",
+                    text=True,
+                    check=True,
+                    stdout=subprocess.PIPE,
+                    stderr=subprocess.PIPE
+                )
+            except subprocess.CalledProcessError as e:
+                logger.error(f"Failed to set password: {e.stderr}")
+                raise e
             
             # Ensure wheel group has sudo privileges
             sudoers_dir = os.path.join(mount_root, "etc/sudoers.d")