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/ARCHITECTURE_CONCELIER.md

@@ -123,6 +123,23 @@ details             // structured conflict explanation / merge reasoning
 - Conflict explainers are serialized as deterministic `MergeConflictExplainerPayload` records (type, reason, source ranks, winning values); replay clients can parse the payload to render human-readable rationales without re-computing precedence.
 - Concelier.WebService exposes the immutable log via `GET /concelier/advisories/{vulnerabilityKey}/replay[?asOf=UTC_ISO8601]`, returning the latest statements (with hex-encoded hashes) and any conflict explanations for downstream exporters and APIs.
 
+**AdvisoryObservation (new in Sprint 24)**
+
+```
+observationId       // deterministic id: {tenant}:{source}:{upstreamId}:{revision}
+tenant              // issuing tenant (lower-case)
+source{vendor,stream,api,collectorVersion}
+upstream{
+    upstreamId, documentVersion, contentHash,
+    fetchedAt, receivedAt, signature{present,format,keyId,signature}}
+content{format,specVersion,raw,metadata}
+linkset{aliases[], purls[], cpes[], references[{type,url}]}
+createdAt           // when Concelier recorded the observation
+attributes          // optional provenance metadata (e.g., batch, connector)
+```
+
+The observation is an immutable projection of the raw ingestion document (post provenance validation, pre-merge) that powers Link‑Not‑Merge overlays and Vuln Explorer. Observations live in the `advisory_observations` collection, keyed by tenant + upstream identity. `linkset` provides normalized aliases/PURLs/CPES that downstream services (Graph/Vuln Explorer) join against without triggering merge logic. Concelier.Core exposes strongly-typed models (`AdvisoryObservation`, `AdvisoryObservationLinkset`, etc.) and a Mongo-backed store for filtered queries by tenant/alias; this keeps overlay consumers read-only while preserving AOC guarantees.
+
 **ExportState**
 
 ```