Add tests and implement StubBearer authentication for Signer endpoints

- Created SignerEndpointsTests to validate the SignDsse and VerifyReferrers endpoints.
- Implemented StubBearerAuthenticationDefaults and StubBearerAuthenticationHandler for token-based authentication.
- Developed ConcelierExporterClient for managing Trivy DB settings and export operations.
- Added TrivyDbSettingsPageComponent for UI interactions with Trivy DB settings, including form handling and export triggering.
- Implemented styles and HTML structure for Trivy DB settings page.
- Created NotifySmokeCheck tool for validating Redis event streams and Notify deliveries.

src/StellaOps.Concelier.WebService/TASKS.md

@@ -16,7 +16,7 @@
 |Batch job definition last-run lookup|BE-Base|Core|DONE – definitions endpoint now precomputes kinds array and reuses batched last-run dictionary; manual smoke verified via local GET `/jobs/definitions`.|
 |Add no-cache headers to health/readiness/jobs APIs|BE-Base|WebService|DONE – helper applies Cache-Control/Pragma/Expires on all health/ready/jobs endpoints; awaiting automated probe tests once connector fixtures stabilize.|
 |Authority configuration parity (FSR1)|DevEx/Concelier|Authority options schema|**DONE (2025-10-10)** – Options post-config loads clientSecretFile fallback, validators normalize scopes/audiences, and sample config documents issuer/credential/bypass settings.|
-|Document authority toggle & scope requirements|Docs/Concelier|Authority integration|**DOING (2025-10-10)** – Quickstart updated with staging flag, client credentials, env overrides; operator guide refresh pending Docs guild review.|
+|Document authority toggle & scope requirements|Docs/Concelier|Authority integration|**DONE (2025-10-21)** – Quickstart now documents staging flag, client credentials, env overrides; operator guide refresh merged. Remaining copy polishing is tracked under `DOCS-CONCELIER-07-201` in `docs/TASKS.md`.|
 |Plumb Authority client resilience options|BE-Base|Auth libraries LIB5|**DONE (2025-10-12)** – `Program.cs` wires `authority.resilience.*` + client scopes into `AddStellaOpsAuthClient`; new integration test asserts binding and retries.|
 |Author ops guidance for resilience tuning|Docs/Concelier|Plumb Authority client resilience options|**DONE (2025-10-12)** – `docs/21_INSTALL_GUIDE.md` + `docs/ops/concelier-authority-audit-runbook.md` document resilience profiles for connected vs air-gapped installs and reference monitoring cues.|
 |Document authority bypass logging patterns|Docs/Concelier|FSR3 logging|**DONE (2025-10-12)** – Updated operator guides clarify `Concelier.Authorization.Audit` fields (route/status/subject/clientId/scopes/bypass/remote) and SIEM triggers.|