feat(governance): Implement policy orchestration layer with policy-as-code

[adwiteeymauriya]

Description

Implement a policy orchestration layer that enables programmable, composable governance building blocks.

Features

Policy-as-Code

• Version-controlled policy definitions in YAML/JSON
• Testable policies with unit tests
• Policy validation and linting

Composable Policies

• Policy inheritance (base policies with domain-specific overrides)
• Policy composition for complex scenarios
• Conflict resolution for overlapping rules

Hot Reload

• Update policies without service restart
• Policy versioning and rollback
• Gradual rollout support

Policy Types

• Access policies (who/what can access which data)
• Transformation policies (how data can be modified)
• Output policies (what AI can generate)
• Retention policies (how long data/logs are kept)
• Escalation policies (when human intervention required)

API Design

POST /api/v1/governance/policies
GET /api/v1/governance/policies
POST /api/v1/governance/policies/compose
POST /api/v1/governance/policies/simulate

Example Policy

policy:
  name: financial_advisory
  inherits: base_compliance
  
  context_requirements:
    data_classification: [internal, confidential]
    user_role: [financial_advisor, compliance_officer]
  
  guardrails:
    - type: output_filter
      config:
        require_disclaimer: true
        block_specific_advice: true
    
    - type: audit
      config:
        log_level: full
        retention_days: 2555  # 7 years

Acceptance Criteria

• Policy CRUD API implemented
• Policy composition and inheritance working
• Hot reload without downtime
• Policy simulation endpoint functional
• Integration with Context Engine
• Policy versioning and audit trail