Cover PromptKit catalog command behavior

docs/roadmap/implementation.md

@@ -1,6 +1,6 @@
 # Implement PromptKit comparison and catalogs
 
-Status: Stages 1–7 complete; remaining stages are planned.
+Status: Stages 1–8 complete; remaining stages are planned.
 
 ## Scope and authority
 
@@ -480,6 +480,26 @@ Run focused catalog and existing named-show tests through assembled public
 commands. Native membership belongs to Stage 5. Add no provider network access,
 benchmark thresholds, concurrency guarantees, or general fixture framework.
 
+**Completion evidence (2026-10-12)**
+
+- Expanded assembled-command coverage for independent prompts/profiles, mixed
+  show/list trees, catalog-only help, existing show-only and valid-absence
+  behavior, and nil-loader errors after all four callbacks are cleared.
+- Verified construction, installation, help, and version do not invoke suite
+  factories or providers. Help with a supplied selector still converts it.
+  Invocation tests observe one input and state after checks, usage rejection
+  before acquisition, nil-factory zero values, original selector capture,
+  supplied empty/false/zero/repeated values, and fresh values on a second run.
+- Decoded command output to verify prompt `id`/`version` string fields, profile
+  string sequences, no envelope, exact values and order, default and explicit
+  YAML, and `[]` for nil and allocated-empty inventories. Extra operands and
+  unavailable version/scope flags fail as usage without reaching providers.
+- Covered provider error identity and diagnostics, cancellation after provider
+  completion preventing output, report writer errors, and short writes with
+  incomplete-report state and retained diagnostics.
+- Focused assembled catalog/named-show tests and the complete ckprompt package
+  suite passed with `GOTOOLCHAIN=local go test -count=1`.
+
 ## Stage 9: Demonstrate capabilities in the composed consumer
 
 **Outcome:** the maintained example exercises both features through bundled