Configure Docker authentication for Artifact Registry

[yolocs]

🥞 Stacked PR (generated by git ns)

Use this link to review incremental changes.

• dar-configure-docker [Files changed]
  • dar-configure-docker-setup [Files changed]

---

Changes

Add the experimental databricks auth docker configure [PROFILE] --region REGION command. It configures Docker's credential helper and installs docker-credential-databricks beside the running CLI: a shell shim on Unix and a .cmd shim on Windows. Both invoke databricks auth docker token for Docker's get operation.

Why

Docker needs a discoverable helper that requests a fresh workspace OAuth token for each Artifact Registry operation without persisting the token in Docker configuration.

Tests

• go test ./libs/dockercredentials ./cmd/auth/docker ./cmd/auth ./cmd/root -count=1: pass
• go test ./acceptance -run 'TestAccept/cmd/auth/docker' -tail -test.v -count=1: pass
• Affected Go formatting and lint (0 issues), tidy, whitespace, dead-code, and changelog checks: pass
• Windows and macOS CLI cross-builds: pass
• ./task test: 5,167 tests, 6 skipped, 43 unrelated bundle acceptance snapshot failures on the updated upstream base

This PR was written by Codex.

[github-actions]

Approval status: pending

/cmd/auth/ - needs approval

9 files changed
Suggested: @simonfaltum
Also eligible: @renaudhartert-db, @mihaimitrea-db, @tanmay-db, @Divyansh-db, @hectorcast-db, @parthban-db, @tejaskochar-db, @chrisst, @rauchy

General files (require maintainer)

23 files changed
Based on git history:

• @simonfaltum -- recent work in cmd/auth/

_{Any maintainer (@andrewnester, @anton-107, @denik, @pietern, @shreyas-goenka, @simonfaltum, @renaudhartert-db, @janniklasrose, @lennartkats-db, @rugpanov, @rclarey) can approve all areas.
See OWNERS for ownership rules.}

[pietern]

You can add shim_windows.go and shim_other.go and use build tags, unless you want to test the Windows paths on Linux.

[yolocs]

Yes, this is intentional so we can exercise Windows shim generation and lookup behavior on Linux CI. The actual cmd.exe execution tests remain Windows-only. Build tags would prevent that cross-platform coverage, so I prefer to keep the current structure if you don't object

[github-actions]

An authorized user can trigger integration tests manually by following the instructions below:

Trigger:
go/deco-tests-run/cli

Inputs:

• PR number: 6336
• Commit SHA: 1e1a4acad48f6d3d5e62c68638b15c135e637db2

Checks will be approved automatically on success.

[pietern]

Superseded by #6700, recreated on a branch in this repo (not a fork) so CI runs. Stacked on #6699; same content, authorship preserved.