Add sample proof bundle configurations and verification script

- Introduced sample proof bundle configuration files for testing, including `sample-proof-bundle-config.dsse.json`, `sample-proof-bundle.dsse.json`, and `sample-proof-bundle.json`.
- Implemented a verification script `test_verify_sample.sh` to validate proof bundles against specified schemas and catalogs.
- Updated existing proof bundle configurations with new metadata, including versioning, created timestamps, and justification details.
- Enhanced evidence entries with expiration dates and hashes for better integrity checks.
- Ensured all new configurations adhere to the defined schema for consistency and reliability in testing.

src/Notifier/StellaOps.Notifier/TASKS.md

@@ -13,3 +13,4 @@
 | NOTIFY-RISK-66-001 | DONE (2025-11-24) | Notifications Service Guild · Risk Engine Guild | Added risk-events endpoint + templates/rules for severity change notifications. | 
 | NOTIFY-RISK-67-001 | DONE (2025-11-24) | Notifications Service Guild · Policy Guild | Added routing/templates for risk profile publish/deprecate/threshold change. | 
 | NOTIFY-RISK-68-001 | DONE (2025-11-24) | Notifications Service Guild | Default routing seeds with throttles/locales for risk alerts. | 
+| NOTIFY-GAPS-171-014 | BLOCKED (2025-12-04) | Notifications Service Guild | Waiting on NR1–NR10 specifics in `31-Nov-2025 FINDINGS.md` and schema/catalog refresh before remediation can start. |