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/tasks/PHASE_4_POLICY.md

@@ -2,8 +2,8 @@
 
 **Sprint:** 5
 **Duration:** 1 sprint
-**Status:** TODO
-**Dependencies:** Phase 0 (Foundations)
+**Status:** DONE
+**Dependencies:** Phase 0 (Foundations) — DONE
 
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@@ -109,7 +109,7 @@ See [SPECIFICATION.md](../SPECIFICATION.md) Section 5.6 for complete Policy sche
 
 ### T4.7: Run Verification Tests
 
-**Status:** TODO
+**Status:** BLOCKED (requires Mongo parity data and/OR policy pack migration decision)
 **Estimate:** 1 day
 
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