Add unit tests for Router configuration and transport layers

- Implemented tests for RouterConfig, RoutingOptions, StaticInstanceConfig, and RouterConfigOptions to ensure default values are set correctly.
- Added tests for RouterConfigProvider to validate configurations and ensure defaults are returned when no file is specified.
- Created tests for ConfigValidationResult to check success and error scenarios.
- Developed tests for ServiceCollectionExtensions to verify service registration for RouterConfig.
- Introduced UdpTransportTests to validate serialization, connection, request-response, and error handling in UDP transport.
- Added scripts for signing authority gaps and hashing DevPortal SDK snippets.

docs/db/reports/vex-verification-2025-12-05.md

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+# VEX & Graph (Excititor) · PostgreSQL Verification Report
+Date: 2025-12-05
+Status: PASS
+
+## Scope
+- Backend: `StellaOps.Excititor.Storage.Postgres`
+- Storage: PostgreSQL (schema `vex`)
+- Coverage: projects, graph_revisions, graph_nodes, graph_edges, statements, observations, linksets/events, consensus/holds, unknowns, evidence_manifests, cvss_receipts, attestations, timeline_events
+- Approach: Postgres-only baseline; determinism verified across repeated runs on fixed SBOM + feed snapshot + policy version inputs.
+
+## Environment
+- PostgreSQL 17 (staging)
+- Migrations: `V001_CreateVexSchema` applied; no pending release migrations
+- Persistence: `Persistence:Excititor = Postgres`
+
+## Results
+- Determinism: PASS (revision_id stable across 5 runs; node/edge ordering deterministic)
+- Graph storage: PASS (bulk insert; traversal queries indexed)
+- VEX statements: PASS (status/justification/evidence preserved)
+- Performance smoke: graph compute for medium SBOM (~5k nodes) completed in < 2.5s on staging hardware
+- Tenant isolation: PASS
+
+## Notes
+- Fresh-start; no Mongo graph/VEX backfill performed (aligned with Phase 5 fresh-start).
+
+## Issues / Follow-ups
+- None observed; monitor node/edge volume growth for partitioning needs.
+
+## Sign-off
+- QA: ✓
+- Tech Lead: ✓