chore: update task statuses to completed for graph-validation, host-graphology, graph-construction-operation, reactive-workflow-root

tasks/graph-construction-operation.md

@@ -1,7 +1,7 @@
 ---
 id: graph/construction-operation
 name: Implement operation graph construction (fromSpecs, addOperation, addTypedEdge)
-status: pending
+status: completed
 depends_on:
   - graph/flowgraph-class
 scope: moderate

tasks/reactive-workflow-root.md

@@ -1,7 +1,7 @@
 ---
 id: reactive/workflow-root
 name: Implement WorkflowReactiveRoot — signal graph, EventLogProjection, lifecycle, abort, dispose
-status: pending
+status: completed
 depends_on:
   - graph/flowgraph-class
   - schema/enums