Track 5: Split deploy/ into target modules

[nielsweistra]

Track 5: Split deploy/ into target modules

Overview

deploy/ contains logic for deploying policies to multiple targets (Azure Policy,
Kubernetes OPA/Gatekeeper, etc.) in a single file. This makes it hard to add new
targets or test them in isolation.

Target Structure

deploy/
├── __init__.py         (re-exports for backward compatibility)
├── azure.py            (Azure Policy deployment logic)
└── kubernetes.py       (Kubernetes OPA/Gatekeeper deployment logic)

Implementation Steps

1. Create src/itl_policy_builder/deploy/ as a package
2. Move Azure deployment logic to deploy/azure.py
3. Move Kubernetes deployment logic to deploy/kubernetes.py
4. Update deploy/__init__.py to re-export all public functions for backward compatibility
5. Update any internal imports that reference the old module path

Acceptance Criteria

• from itl_policy_builder.deploy import deploy_to_azure (and all others) still works
• from itl_policy_builder.deploy.azure import deploy_to_azure also works
• All existing tests pass unchanged
• New deployment targets can be added as deploy/newplatform.py without touching other files
• No circular imports