Update AzureAuth to 0.9.6 for macOS broker support

[krubenok]

Summary

• Update the bundled AzureAuth CLI from 0.8.4 to 0.9.6.
• Update AzureAuth release artifact names for the current Windows packages, including win-arm64.
• Document the macOS broker opt-in path for azureauth, ado-npm-auth, and the Yarn plugin.

Draft status / blocker

This is intentionally a draft. AzureAuth 0.9.6 contains macOS broker support, but local validation shows the Azure DevOps PAT path does not work yet with the built-in ADO client registration.

The failing path is:

node packages/node-azureauth/scripts/azureauth.cjs ado pat \
  --mode broker \
  --organization outlookweb \
  --display-name local-macos-broker-test \
  --prompt-hint "Authenticate to outlookweb for local macOS broker test" \
  --scope vso.packaging_write \
  --output json \
  --timeout 30 \
  --verbosity debug

That fails in broker token acquisition with WAM error -51411, ApiContractViolation, and AADSTS50011. The narrower AAD repro using AzureAuth's built-in Azure DevOps parameters also fails with the same 51411 error:

node packages/node-azureauth/scripts/azureauth.cjs aad \
  --client 872cd9fa-d31f-45e0-9eab-6e460a02d1f1 \
  --tenant 72f988bf-86f1-41af-91ab-2d7cd011db47 \
  --scope 499b84ac-1321-427f-aa17-267ca6975798/.default \
  --mode broker \
  --prompt-hint "Test Azure DevOps client broker redirect" \
  --output none \
  --timeout 1 \
  --verbosity debug

AzureAuth 0.9.6 uses the macOS broker redirect URI msauth.com.msauth.unsignedapp://auth. That redirect URI needs to be added to the app registration for client 872cd9fa-d31f-45e0-9eab-6e460a02d1f1 before this PR can be validated end to end.

Validation

• yarn workspace azureauth test
• yarn prettier --check packages/node-azureauth/README.md packages/ado-npm-auth/README.md packages/yarn-plugin-ado-auth/README.md
• node packages/node-azureauth/scripts/azureauth.cjs --version reports 0.9.6.0
• Web auth control path succeeds for ado pat --mode web; broker path is blocked by the app-registration redirect URI issue above.