feat: add client credentials unattended auth flow

[cristipufu]

Pull Request Overview

This PR adds a client credentials unattended authentication flow to the CLI tool.

• Introduces new CLI options (--client-id, --client-secret, --base-url) to facilitate unattended authentication.
• Implements a new authentication branch in auth() to handle client credentials and falls back to interactive mode when credentials are not provided.
• Adds a new module (src/uipath/_cli/_auth/_client_credentials.py) that encapsulates the client credentials authentication logic.

Usage Example

The external app needs the OR.Execution Orchestrator scope for package publishing.

uipath auth --client-id='12345678-c4c5-4f1f-93ff-4f5ab47d57ea' --client-secret='xxx' --base-url='https://alpha.uipath.com/account/tenant'

uipath publish --tenant

Ref: #388
Ref: UiPath/uipath-langchain-python#96

Development Package

• Add this package as a dependency in your pyproject.toml:

[project]
dependencies = [
  # Exact version:
  "uipath==2.0.64.dev1004040439",

  # Any version from PR
  "uipath>=2.0.64.dev1004040000,<2.0.64.dev1004050000"
]

[[tool.uv.index]]
name = "testpypi"
url = "https://test.pypi.org/simple/"
publish-url = "https://test.pypi.org/legacy/"
explicit = true

[tool.uv.sources]
uipath = { index = "testpypi" }

[Copilot]

Pull Request Overview

This PR adds a client credentials unattended authentication flow to the CLI tool.

• Introduces new CLI options (--client-id, --client-secret, --scope, --base-url) to facilitate unattended authentication.
• Implements a new authentication branch in auth() to handle client credentials and falls back to interactive mode when credentials are not provided.
• Adds a new module (src/uipath/_cli/_auth/_client_credentials.py) that encapsulates the client credentials authentication logic.

Reviewed Changes

Copilot reviewed 2 out of 2 changed files in this pull request and generated no comments.

File	Description
src/uipath/_cli/cli_auth.py	Updated auth() to support client credentials flow with new CLI options.
src/uipath/_cli/_auth/_client_credentials.py	New module implementing the client credentials authentication flow.

Comments suppressed due to low confidence (1)

src/uipath/_cli/cli_auth.py:103

• Consider validating that both client_id and client_secret are provided together. If only one of these is specified, prompt the user with an explicit error message rather than silently falling back to the interactive flow.

if client_id and client_secret: