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/cluster-provisioning.md

@@ -0,0 +1,21 @@
+# PostgreSQL Cluster Provisioning Inputs (staging / production)
+
+Fill this template before marking T0.1 complete. One row per environment.
+
+| Env | Host | Port | DB name | User | Password/Secret ref | Pooling (min/max) | Backup owner & cadence | Monitoring owner & target (Prom/Grafana) | Connection options (SSL, timeout) | Notes |
+| --- | ---- | ---- | ------- | ---- | ------------------- | ----------------- | ---------------------- | ---------------------------------------- | --------------------------------- | ----- |
+| Staging | postgres-staging.internal | 5432 | stellaops | stellaops_app | ${POSTGRES_STAGING_PASSWORD:?} | min=5 / max=20 | DevOps · daily full + WAL | DevOps · prom-staging / grafana-staging | SSL required; stmt_timeout=30s | CONFIRMED 2025-12-05 |
+| Prod | postgres-prod.internal | 5432 | stellaops | stellaops_app | ${POSTGRES_PROD_PASSWORD:?} | min=5 / max=30 | DevOps · daily full + WAL + weekly PITR drill | DevOps · prom-prod / grafana-prod | SSL required; stmt_timeout=30s | CONFIRMED 2025-12-05 |
+
+Provisioning checklist
+- [ ] PostgreSQL 16+ provisioned (HA or single per env)
+- [ ] Network allowlist for app/CI runners
+- [ ] PgBouncer (transaction mode) or equivalent pooler configured
+- [ ] Backups tested (restore drill)
+- [ ] Monitoring/alerts enabled (pg_stat_statements, disk, locks, replication lag)
+- [ ] Credentials stored in secrets manager (link here)
+- [ ] Connection strings injected into app settings / deployment values
+
+Reference
+- See `docs/db/persistence-config-template.yaml` for appsettings structure.
+- See `docs/db/MIGRATION_STRATEGY.md` for migration/lock expectations.