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.

docs/events/samples/scanner.event.scan.completed@1.sample.json

@@ -51,12 +51,20 @@
         "reachability": "runtime"
       }
     ],
-    "links": {
-      "ui": "https://scanner.example/ui/reports/report-abc",
-      "report": "https://scanner.example/api/v1/reports/report-abc",
-      "policy": "https://scanner.example/api/v1/policy/revisions/rev-42",
-      "attestation": "https://scanner.example/ui/attestations/report-abc"
-    },
+    "links": {
+      "report": {
+        "ui": "https://scanner.example/ui/reports/report-abc",
+        "api": "https://scanner.example/api/v1/reports/report-abc"
+      },
+      "policy": {
+        "ui": "https://scanner.example/ui/policy/revisions/rev-42",
+        "api": "https://scanner.example/api/v1/policy/revisions/rev-42"
+      },
+      "attestation": {
+        "ui": "https://scanner.example/ui/attestations/report-abc",
+        "api": "https://scanner.example/api/v1/reports/report-abc/attestation"
+      }
+    },
     "dsse": {
       "payloadType": "application/vnd.stellaops.report+json",
       "payload": "eyJyZXBvcnRJZCI6InJlcG9ydC1hYmMiLCJpbWFnZURpZ2VzdCI6InNoYTI1NjpmZWVkZmFjZSIsImdlbmVyYXRlZEF0IjoiMjAyNS0xMC0xOVQxMjozNDo1NiswMDowMCIsInZlcmRpY3QiOiJibG9ja2VkIiwicG9saWN5Ijp7InJldmlzaW9uSWQiOiJyZXYtNDIiLCJkaWdlc3QiOiJkaWdlc3QtMTIzIn0sInN1bW1hcnkiOnsidG90YWwiOjEsImJsb2NrZWQiOjEsIndhcm5lZCI6MCwiaWdub3JlZCI6MCwicXVpZXRlZCI6MH0sInZlcmRpY3RzIjpbeyJmaW5kaW5nSWQiOiJmaW5kaW5nLTEiLCJzdGF0dXMiOiJCbG9ja2VkIiwic2NvcmUiOjQ3LjUsInNvdXJjZVRydXN0IjoiTlZEIiwicmVhY2hhYmlsaXR5IjoicnVudGltZSJ9XSwiaXNzdWVzIjpbXX0=",