feat: Document completed tasks across multiple components

- Added completed tasks documentation for Scheduler WebService, ImpactIndex, Models, Queue, Storage.Mongo, Worker, Signals, Signer, UI, Zastava.Observer, Zastava.Webhook, Zastava.Core, Cryptography.Kms, Cryptography, and Plugin.
- Each task includes ID, status, owners, dependencies, descriptions, and exit criteria to ensure clarity and traceability.
- Enhanced integration and unit testing coverage across various components to validate functionality and compliance with specifications.

ops/deployment/TASKS.completed.md

@@ -0,0 +1,5 @@
+# Completed Tasks
+
+| ID | Status | Owner(s) | Depends on | Description | Exit Criteria |
+|----|--------|----------|------------|-------------|---------------|
+| DEVOPS-OPS-14-003 | DONE (2025-10-26) | Deployment Guild | DEVOPS-REL-14-001 | Document and script upgrade/rollback flows, channel management, and compatibility matrices per architecture. | Helm/Compose guides updated with digest pinning, automated checks committed, rollback drill recorded. |