[CoR] Remove azd from project deployment prerequisites

[nturinski]

Problem

Create New Project with Copilot currently presents both azd and Azure CLI (az) as deployment prerequisites, while the AppOnboard deployment workflow explicitly prohibits azure.yaml, azd up, azd provision, and azd deploy. This gives users a misleading prerequisite and suggests a deployment path the workflow cannot use.

Proposed work

• Remove azd from the CoR/AppOnboard deployment prerequisite catalog and prerequisite recorder schema.
• Update the deployment-plan refresh prompt to check only Azure CLI (az).
• Update related types, comments, tests, and user documentation.
• Retain shared azd install-link resolution and azd-compatible environment parsing where other workflows still depend on them.

Likely implementation surfaces include:

• src/webviews/copilotOnRails/views/utils/deployPrerequisiteCatalog.ts
• src/chat/tools/copilotOnRails/recordDeployPrerequisitesTool.ts
• src/webviews/copilotOnRails/extension/controllers/DeploymentPlanViewController.ts
• test/copilotOnRails/deployPrerequisites.test.ts
• docs/copilot-create-project.md

Acceptance criteria

• The CoR deployment experience requires and displays Azure CLI (az) only.
• Re-checking deployment prerequisites does not probe or request installation of azd.
• Existing non-CoR consumers of shared azd utilities remain functional.
• Tests and documentation reflect the revised prerequisite contract.