feat: add SWAP partition detection and cleanup before loop device detach

[rpandya28]

Merge Checklist

All boxes should be checked before merging the PR

• The changes in the PR have been built and tested
• Documentation has been updated to reflect the changes (or no doc update needed)
• Ready to merge

Description

Any Newly Introduced Dependencies

How Has This Been Tested?

2026-05-19T11:36:11.361Z INFO imagedisc/loopdev.go:112 Found SWAP partition: /dev/loop32p2, disabling it
2026-05-19T11:36:11.378Z INFO imagedisc/loopdev.go:117 Successfully disabled SWAP on /dev/loop32p2
2026-05-19T11:36:11.383Z INFO rawmaker/rawmaker.go:133 Successfully detached loopback device: /dev/loop32
2026-05-19T11:36:11.383Z INFO display/display.go:21 Checking for image artifacts in: /home/user/riddhi/image-composer-tool/workspace/ubuntu-ubuntu24-x86_64/imagebuild/minimal

[Copilot]

Pull request overview

This PR updates the loop device teardown path in internal/image/imagedisc to proactively detect SWAP partitions on a loop device and disable them before detaching the loop device, aiming to avoid detach failures caused by active swap.

Changes:

• Added a pre-detach SWAP cleanup step in LoopSetupDelete.
• Implemented lsblk -J parsing to locate swap partitions under the target loop device.
• Issued swapoff for detected swap partitions and continued with detach regardless of swap cleanup outcome.

Comments suppressed due to low confidence (1)

internal/image/imagedisc/loopdev.go:66

• LoopSetupDelete now executes lsblk (and potentially swapoff) via shell.ExecCmd before losetup -d. Existing unit tests for LoopSetupDelete (internal/image/imagedisc/loopdev_test.go) only mock the losetup -d ... command, so they will fall back to DefaultExecutor and try to run real lsblk/swapoff during tests. Update the tests/mocks to include the new commands (or refactor to make swap disabling injectable) so CI doesn't execute host commands.

func (loopDev *LoopDev) LoopSetupDelete(loopDevPath string) error {
	// Handle SWAP partitions before detaching
	if err := loopDev.disableSwapPartitions(loopDevPath); err != nil {
		log.Warnf("Warning while disabling SWAP partitions on %s: %v", loopDevPath, err)
		// Don't return error, try to continue with detach
	}

	cmd := fmt.Sprintf("losetup -d %s", loopDevPath)
	if _, err := shell.ExecCmd(cmd, true, shell.HostPath, nil); err != nil {
		log.Errorf("Failed to delete loop device %s: %v", loopDevPath, err)
		return fmt.Errorf("failed to delete loop device %s: %w", loopDevPath, err)