Add in-platform policy editor and test harness

[MuttleyD]

Context

MIDAS is intended to support externalised policy evaluation as part of governed decision execution.

As policy support matures, users will also need practical tools for authoring, validating, and testing policy logic within the platform rather than relying entirely on external workflows.

Problem

There is currently no in-platform policy editor or test harness for policy authoring and validation.

This makes it harder to:

• create and iterate on policies efficiently
• test policy behaviour before deployment
• reduce operational friction around policy changes
• provide a more complete policy management experience within MIDAS

Proposed solution

Add an in-platform policy editor and test harness to MIDAS.

This should allow users to author policy logic, validate it, and test expected behaviour within a controlled platform workflow.

Scope

• define how policy authoring is represented in the platform
• provide a policy editing experience
• provide a test harness for validating policy behaviour
• align authoring and testing with the wider governance and control-plane model where appropriate
• document the authoring and testing workflow

Acceptance criteria

• an in-platform policy editor exists
• a policy test harness exists
• policies can be validated and tested before operational use
• the workflow aligns with the broader policy-management direction of MIDAS
• feature is documented