feat: Initialize Zastava Webhook service with TLS and Authority authentication

- Added Program.cs to set up the web application with Serilog for logging, health check endpoints, and a placeholder admission endpoint.
- Configured Kestrel server to use TLS 1.3 and handle client certificates appropriately.
- Created StellaOps.Zastava.Webhook.csproj with necessary dependencies including Serilog and Polly.
- Documented tasks in TASKS.md for the Zastava Webhook project, outlining current work and exit criteria for each task.

src/StellaOps.Excititor.Attestation/TASKS.md

@@ -4,4 +4,4 @@ If you are working on this file you need to read docs/ARCHITECTURE_EXCITITOR.md
 |---|---|---|---|
 |EXCITITOR-ATTEST-01-001 – In-toto predicate & DSSE builder|Team Excititor Attestation|EXCITITOR-CORE-01-001|**DONE (2025-10-16)** – Added deterministic in-toto predicate/statement models, DSSE envelope builder wired to signer abstraction, and attestation client producing metadata + diagnostics.|
 |EXCITITOR-ATTEST-01-002 – Rekor v2 client integration|Team Excititor Attestation|EXCITITOR-ATTEST-01-001|**DONE (2025-10-16)** – Implemented Rekor HTTP client with retry/backoff, transparency log abstraction, DI helpers, and attestation client integration capturing Rekor metadata + diagnostics.|
-|EXCITITOR-ATTEST-01-003 – Verification suite & observability|Team Excititor Attestation|EXCITITOR-ATTEST-01-002|TODO – Add verification helpers for Worker/WebService, metrics/logging hooks, and negative-path regression tests.|
+|EXCITITOR-ATTEST-01-003 – Verification suite & observability|Team Excititor Attestation|EXCITITOR-ATTEST-01-002|DOING (2025-10-19) – Add verification helpers for Worker/WebService, metrics/logging hooks, and negative-path regression tests. Draft plan logged in `EXCITITOR-ATTEST-01-003-plan.md` (2025-10-19).|