chore: prepare CLI repo rename

[jy-tan]

Summary

Prepare the CLI repo for the tusk-cli GitHub rename and matching release artifact rename. This updates the release, installer, updater, and documentation paths to target the new repo slug while intentionally leaving the Go module path unchanged for now.

Changes

• Configure GoReleaser to publish tusk-cli_* artifacts and stop hardcoding the old GitHub repo slug
• Update the installer and self-update download paths to use Use-Tusk/tusk-cli
• Switch the update manifest reference to the stable https://cli.usetusk.ai/latest.json URL
• Update the release workflow to publish release links using the current GitHub repository name
• Refresh README, onboarding links, issue links, and release helper output to point at Use-Tusk/tusk-cli
• Add updater tests that cover the new download URL construction for Linux and macOS

Notes

• This PR is intended to merge immediately after the GitHub repo rename, since the updated release and install paths already point at Use-Tusk/tusk-cli.
• The Go module path and internal import paths still remain github.com/Use-Tusk/tusk-drift-cli in this PR and can be renamed in a follow-up change.
• Existing released CLI binaries will not auto-update cleanly to the first renamed release, because older versions still point at the tusk-drift-cli updater and release paths. New binaries built from this PR will update correctly.
• For existing customers:
  • Customers with an already-installed CLI will need to reinstall manually or rerun the install script.
  • Customers using drift-action in its default release-install mode are unlikely to be immediately affected, since it installs from https://cli.usetusk.ai/install.sh.
  • Customers using drift-action with cli-source: source will need the drift-action update as well.
  • CI workflows that directly reference Use-Tusk/tusk-drift-cli or tusk-drift-cli_* release assets will need to be updated.

[cubic-dev-ai]

1 issue found across 13 files

Prompt for AI agents (unresolved issues)

Check if these issues are valid — if so, understand the root cause of each and fix them. If appropriate, use sub-agents to investigate and fix each issue separately.


<file name="internal/version/update_test.go">

<violation number="1" location="internal/version/update_test.go:53">
P2: This test should not run in parallel because it mutates shared package globals (`runtimeGOOS`/`runtimeGOARCH`), which can race with the other new test and make assertions flaky.</violation>
</file>

_{Reply with feedback, questions, or to request a fix. Tag @cubic-dev-ai to re-run a review.}