Complete workplan state model cleanup

docs/task-flow-engine-spec.md

@@ -129,10 +129,10 @@ blocking_assertions:
     passed: false
     reason: "Expected all values at tasks.*.status to be in ['done', 'cancelled']; got ['done', 'todo']."
 reachable:
-  - todo
+  - ready
   - active
 unreachable:
-  - workstation: completed
+  - workstation: finished
     blocking:
       id: tasks.all_done
       passed: false
@@ -151,9 +151,9 @@ Schema:
 
 ### Workstreams
 
-Workstreams can express readiness for completion by asserting that child tasks
+Workstreams can express readiness for closure by asserting that child tasks
 are `done` or `cancelled`. They can express dependency blocking by checking that
-all dependency workstreams have reached `completed`.
+all dependency workstreams have reached `finished` or `archived`.
 
 ### Tasks