Add debug events to command execution

docs/roadmap/implementation.md

@@ -1,6 +1,6 @@
 # Invocation reporting implementation plan
 
-Status: Stages 1–8 complete. Stage 9 is next.
+Status: Stages 1–9 complete. Stage 10 is next.
 
 ## Objective and authority
 
@@ -349,7 +349,7 @@ scheduled for the later suite reconciliation.
 
 ## Stage 9: Add core debug events
 
-Status: pending.
+Status: complete.
 
 1. Instrument routing, command-alias resolution, verbosity selection, and handler
    completion. Explain the relevant entered/canonical paths and decisions.
@@ -371,6 +371,13 @@ Validation: `--verbose --debug` reveals earlier selection events;
 explanation, absence of completion when no handler runs, and debug delivery
 failure. Assert selected meaning and order rather than incidental prose.
 
+Routing, reporting-mode selection, and handler-completion events now use shared
+Debug reporting. Early events are submitted after mode selection, and completion
+is submitted after deferred messages. Focused tests cover alias identity,
+selection order, quiet suppression, completion ordering, no-handler behavior,
+cause privacy, and debug delivery failure. Internal suites pass; execution of
+root tests remains deferred until the legacy external callers are reconciled.
+
 ## Stage 10: Separate ConfigKit provider messages and explanations
 
 Status: pending.