Add captured flag value application

docs/roadmap/implementation.md

@@ -1,6 +1,6 @@
 # Implement the optional integration modules and captured registration API
 
-Status: implementation in progress. Stages 1 through 3 are complete; subsequent work follows the ordered roadmap.
+Status: implementation in progress. Stages 1 through 4 are complete; subsequent work follows the ordered roadmap.
 Execute the stages in order. Each stage is sized as a separate Luna coding-agent
 assignment. This document authorizes no publication or changes to sibling
 repositories.
@@ -254,10 +254,14 @@ checks. No new grammar restriction was added.
    materialize or apply the target's input. Scope inapplicability never skips
    supplied-value conversion.
 
-**Completion evidence:** original/copied/lookalike identity, defaults and presence,
-selected required flags, wrapped errors, nil destination, empty selection,
-repeatable independence, and no second conversion. Check both ordinary and
-captured bindings through the same preparation path.
+**Completion evidence — complete:** `CaptureFlags` stores invocation-local
+prepared values by original binding identity, and `ApplyTo` accepts copied handles
+while rejecting lookalikes, uncaptured handles, and nil destinations with
+`ErrFlagWiring`. Required checks apply only to selected bindings and match
+`ErrFlagInput`; defaults and explicit presence are retained. Nil accessors and
+invalid inner bindings are rejected at installation. Repeat applications copy
+core-owned slices without reconversion. Wrapped wiring/input errors route to
+operational/usage outcomes respectively. Root tests pass.
 
 ## Stage 5: Compile typed runners and real built-in declarations