feat(docs): Add comprehensive documentation for Vexer, Vulnerability Explorer, and Zastava modules

- Introduced AGENTS.md, README.md, TASKS.md, and implementation_plan.md for Vexer, detailing mission, responsibilities, key components, and operational notes.
- Established similar documentation structure for Vulnerability Explorer and Zastava modules, including their respective workflows, integrations, and observability notes.
- Created risk scoring profiles documentation outlining the core workflow, factor model, governance, and deliverables.
- Ensured all modules adhere to the Aggregation-Only Contract and maintain determinism and provenance in outputs.

src/Policy/__Libraries/StellaOps.Policy/AGENTS.md

@@ -1,12 +1,12 @@
-# StellaOps.Policy — Agent Charter
-
-## Mission
-Deliver the policy engine outlined in `docs/ARCHITECTURE_SCANNER.md` and related prose:
-- Define YAML schema (ignore rules, VEX inclusion/exclusion, vendor precedence, license gates).
-- Provide policy snapshot storage with revision digests and diagnostics.
-- Offer preview APIs to compare policy impacts on existing reports.
-
-## Expectations
-- Coordinate with Scanner.WebService, Feedser, Vexer, UI, Notify.
-- Maintain deterministic serialization and unit tests for precedence rules.
-- Update `TASKS.md` and broadcast contract changes.
+# StellaOps.Policy — Agent Charter
+
+## Mission
+Deliver the policy engine outlined in `docs/modules/scanner/ARCHITECTURE.md` and related prose:
+- Define YAML schema (ignore rules, VEX inclusion/exclusion, vendor precedence, license gates).
+- Provide policy snapshot storage with revision digests and diagnostics.
+- Offer preview APIs to compare policy impacts on existing reports.
+
+## Expectations
+- Coordinate with Scanner.WebService, Feedser, Vexer, UI, Notify.
+- Maintain deterministic serialization and unit tests for precedence rules.
+- Update `TASKS.md` and broadcast contract changes.