Clarify collection contracts and migration docs

docs/internal/runner.md

@@ -32,6 +32,13 @@ The runner has no durable run or session store.
 
 ## Shared Prompt Selection
 
+The internal engine applies each namespace view to slashless caller selections
+before they reach the runner. The runner therefore selects captured prompts and
+profiles by the resulting exact runtime IDs. Already-qualified selections pass
+through, while configured defaults and stored references are used as authored
+and are not requalified. Prompt version labels are returned as optional
+descriptive metadata; they are not prompt selectors.
+
 Ordinary preparation selects the full prompt definition and construction-time
 hash. It retains its early request-ID check before direct-session
 normalization. Referenced message content and static template syntax were
@@ -73,10 +80,12 @@ exact contract.
 ## Smoke-Test Diagnostics
 
 The separate `SmokeTester` in `internal/usecase` selects from the same captured
-configuration snapshot and backend/profile collaborators as the runner. Explicit
-profile selection takes precedence over prompt-default selection and a backend
-diagnostic default; HTTP-only selection does not resolve a default inference
-profile. Exact public selection rules belong to the root
+configuration snapshot and backend/profile collaborators as the runner. The
+internal engine applies namespace-view qualification to slashless caller IDs
+before diagnostic selection; captured defaults and references remain exact.
+Explicit profile selection takes precedence over prompt-default selection and a
+backend diagnostic default; HTTP-only selection does not resolve a default
+inference profile. Exact public selection rules belong to the root
 [`Engine.SmokeTest` GoDoc](../../smoke_diagnostics.go).
 
 Diagnostics do not call `Run`, `Prepare`, or the prompt preparation pipeline.