feat(bootstrap-gcp): install from local package

[NautiluX]

• Upload a locally built/downloaded package to the
• Install from the local package
• Enable UseConcurrentWrites in sftp client to speedup transfer of large files

[Copilot]

Pull request overview

This PR adds support for installing Codesphere from a locally built or downloaded package file in the GCP bootstrap process, as an alternative to downloading from the portal. The implementation includes validation to ensure local packages and remote versions are not specified simultaneously, file existence checks for local packages, and SFTP performance optimization for file uploads.

Changes:

• Added --install-local CLI flag to specify a local package path for installation
• Enhanced validation to handle mutually exclusive local vs remote installation modes
• Modified installation logic to copy local packages to the jumpbox when specified
• Enabled concurrent writes in SFTP client for improved file upload performance

Reviewed changes

Copilot reviewed 5 out of 5 changed files in this pull request and generated 3 comments.

File	Description
cli/cmd/bootstrap_gcp.go	Adds --install-local flag to CLI
internal/bootstrap/gcp/gcp.go	Adds InstallLocal field, refactors validation into separate functions, updates installation logic to support local packages
internal/bootstrap/gcp/gcp_test.go	Reorganizes tests into clearer contexts and adds comprehensive test coverage for local package scenarios
internal/installer/node/node.go	Enables concurrent writes in SFTP client for better performance

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[joka134]

Looks good. Just a few minor comments related to personal taste. So if you decide to ignore them, that's fine by me 😆

[joka134]

lgtm