Detach version labels in prepared execution snapshots

docs/roadmap/remediation.md

@@ -1,6 +1,6 @@
 # Configuration Collections Implementation Review Findings
 
-Status: Finding 1 completed; Findings 2–3 open. Review completed 2026-10-17.
+Status: Findings 1–2 completed; Finding 3 open. Review completed 2026-10-17.
 
 Reviewed implementation after `89af2a1` through `0221cd4` against the accepted
 [feature roadmap](configuration-collections.md), [implementation plan](implementation.md),
@@ -89,7 +89,7 @@ and public API tests, configuration vet, and `git diff --check`.
 
 ## Finding 2: Detach The Optional Label In Internal Prepared Snapshots
 
-Priority: P3. Status: open.
+Priority: P3. Status: completed 2026-10-17.
 
 Location: [clonePreparedRun](../../internal/usecase/prepared_execution.go),
 lines 226–244; also its use by `PrepareExecution` and `PreparedExecution.Details`.
@@ -121,6 +121,14 @@ non-nil version label. Mutation of one returned internal snapshot must not chang
 retained details, the execution snapshot, or a later result. Reuse existing
 nil/empty public metadata coverage rather than reproducing it at every layer.
 
+Completion: the prepared-run copier now detaches the optional version label with
+the existing nil-aware helper. Extended the owning prepared-execution snapshot
+test to mutate source and returned labels and verify later details, execution
+metadata, and post-execution details remain unchanged. The regression failed
+before the fix and passes afterward. Validation passed with `GOWORK=off`:
+the focused regression, `go test -race ./...`, `go vet ./...`, all three offline
+examples, and `git diff --check`.
+
 ## Finding 3: Document Engine Ownership In Terms Of The Shared Assembly
 
 Priority: P3. Status: open.

internal/usecase/prepared_execution.go

@@ -229,6 +229,7 @@ func clonePreparedRun(source *domain.PreparedRun) (*domain.PreparedRun, error) {
 	}
 
 	copied := *source
+	copied.PromptVersion = copyStringPointer(source.PromptVersion)
 	extraParams, err := jsonvalue.CopyMap(source.EffectiveModelParams.ExtraParams)
 	if err != nil {
 		return nil, err

internal/usecase/prepared_execution_test.go

@@ -662,6 +662,7 @@ func TestRunnerPreparedExecutionDetachesTransferredSnapshotSources(t *testing.T)
 				"properties": map[string]any{"value": map[string]any{"type": "string"}},
 			}
 			definition := promptDef(domain.FormatJSON, domain.ValidationJSONSchema, 0)
+			wantPromptVersion := *definition.Version
 			definition.Validation.SchemaPath = "schema.json"
 			control := &domain.CacheControl{Type: domain.CacheControlEphemeral, TTL: "1h"}
 			rendered := &domain.RenderedPrompt{Messages: []domain.RenderedMessage{{
@@ -697,6 +698,7 @@ func TestRunnerPreparedExecutionDetachesTransferredSnapshotSources(t *testing.T)
 			}
 			mutateExtra(profileExtras, "mutated profile source")
 			mutateExtra(requestExtras, "mutated request source")
+			*definition.Version = "mutated definition label"
 			rendered.Messages[0].Content = "mutated renderer source"
 			control.TTL = "mutated renderer cache metadata"
 			schemaDocument["properties"].(map[string]any)["value"].(map[string]any)["type"] = "integer"
@@ -711,11 +713,21 @@ func TestRunnerPreparedExecutionDetachesTransferredSnapshotSources(t *testing.T)
 				details.StructuredOutput.JSONSchema.Schema.(map[string]any)["properties"].(map[string]any)["value"].(map[string]any)["type"] != "string" {
 				t.Fatalf("prepared details retained a source alias: %#v", details)
 			}
+			if details.PromptVersion == nil || *details.PromptVersion != wantPromptVersion {
+				t.Fatalf("prepared details did not preserve the captured version: %+v", details)
+			}
+			*details.PromptVersion = "mutated details label"
+			if again := prepared.Details(); again == nil || again.PromptVersion == nil || *again.PromptVersion != wantPromptVersion {
+				t.Fatalf("details version mutation escaped into the retained snapshot: %+v", again)
+			}
 
 			result, err := runner.RunPrepared(context.Background(), prepared)
 			if err != nil || result == nil || !result.Validation.IsValid || result.InputHashes["transcript"] != "captured-input-hash" {
 				t.Fatalf("run prepared snapshot=(%+v, %v)", result, err)
 			}
+			if result.PromptVersion == nil || *result.PromptVersion != wantPromptVersion {
+				t.Fatalf("details version mutation escaped into execution metadata: %+v", result)
+			}
 			if len(llmClient.lastReq.Prompt.Messages) != 1 || llmClient.lastReq.StructuredOutput == nil ||
 				llmClient.lastReq.StructuredOutput.JSONSchema == nil ||
 				extraLabel(llmClient.lastReq.Target.ExtraParams) != wantLabel ||
@@ -725,6 +737,7 @@ func TestRunnerPreparedExecutionDetachesTransferredSnapshotSources(t *testing.T)
 				t.Fatalf("execution snapshot retained a source alias: %#v", llmClient.lastReq)
 			}
 			if completedDetails := prepared.Details(); completedDetails == nil ||
+				completedDetails.PromptVersion == nil || *completedDetails.PromptVersion != wantPromptVersion ||
 				len(completedDetails.Messages) != 1 || completedDetails.Messages[0].Content != "captured rendering" ||
 				extraLabel(completedDetails.EffectiveModelParams.ExtraParams) != wantLabel {
 				t.Fatalf("completed details changed after source mutation: %#v", completedDetails)