Add Policy DSL Validator, Schema Exporter, and Simulation Smoke tools

- Implemented PolicyDslValidator with command-line options for strict mode and JSON output.
- Created PolicySchemaExporter to generate JSON schemas for policy-related models.
- Developed PolicySimulationSmoke tool to validate policy simulations against expected outcomes.
- Added project files and necessary dependencies for each tool.
- Ensured proper error handling and usage instructions across tools.

docs/devops/policy-schema-export.md

@@ -0,0 +1,25 @@
+# Policy Schema Export Automation
+
+This utility generates JSON Schema documents for the Policy Engine run contracts.
+
+## Command
+
+```
+scripts/export-policy-schemas.sh [output-directory]
+```
+
+When no output directory is supplied, schemas are written to `docs/schemas/`.
+
+The exporter builds against `StellaOps.Scheduler.Models` and emits:
+
+- `policy-run-request.schema.json`
+- `policy-run-status.schema.json`
+- `policy-diff-summary.schema.json`
+- `policy-explain-trace.schema.json`
+
+## CI integration checklist
+
+- [ ] Invoke the script in the DevOps pipeline (see `DEVOPS-POLICY-20-004`).
+- [ ] Publish the generated schemas as pipeline artifacts.
+- [ ] Notify downstream consumers when schemas change (Slack `#policy-engine`, changelog snippet).
+- [ ] Gate CLI validation once schema artifacts are available.