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.

docs/updates/2025-10-19-platform-events.md

@@ -0,0 +1,10 @@
+# Platform Events Update — 2025-10-19
+
+**Subject:** Canonical event samples enforced across tests & CI  
+**Audience:** Platform Events Guild, Notify Guild, Scheduler Guild, Docs Guild
+
+- Scanner WebService contract tests deserialize `scanner.report.ready@1` and `scanner.scan.completed@1` samples, validating DSSE payloads and canonical ordering via `NotifyCanonicalJsonSerializer`.
+- Notify and Scheduler model suites now round-trip the published event samples (including `attestor.logged@1` and `scheduler.rescan.delta@1`) to catch drift in consumer expectations.
+- Docs CI (`.gitea/workflows/docs.yml`) validates every sample against its schema with `ajv-cli`, keeping offline bundles and repositories aligned.
+
+No additional follow-ups — downstream teams can rely on the committed samples for integration coverage.