Validate source versions in recursive imports

docs/roadmap/implementation.md

@@ -1,6 +1,6 @@
 # Implement shared source version checks
 
-Status: Stages 1–4 complete; recursive import integration has not started.
+Status: Stages 1–5 complete; direct underlay integration has not started.
 
 Audience: a Luna coding agent implementing one numbered stage per prompt, in
 order. The [feature roadmap](source-version-checks.md) owns target behavior and
@@ -343,6 +343,27 @@ The engine mode remains private; public options are scheduled separately.
 Validate: import/glob/destination/accounting/version tests and everyday check.
 Done: imports use one policy without lost warnings or changed physical traversal.
 
+Completion evidence: threaded one per-load source-version state through the
+main import entry and recursive traversal. Each parsed child is checked against
+its source-local rule before placement; accepted headers are removed from an
+owned payload while the original root still supplies raw byte/node charges and
+the processor's original import declarations drive nested traversal. Effective
+main ownership is checked against the remaining placed payload. Evidence is
+retained with the acquired SourceID, and warning diagnostics accumulate without
+stopping traversal. Existing identity, cycle, optional-source, source-record,
+resource-context, and accounting paths remain in use. Added coverage for nested
+and glob imports at mounted relative destinations, accepted unequal declarations,
+rejected hidden declarations, required omissions with source-local locations,
+optional missing imports, evidence identity, and raw header byte/node charges. The
+existing default import-version failure coverage also passes. These checks
+passed with Go `go1.26.8 linux/amd64`:
+
+- `GOTOOLCHAIN=local GOPROXY=off go test ./internal/engine -run 'SourceVersion|Version|Import|Glob|Destination' -count=1`
+- `GOTOOLCHAIN=local ./scripts/check.sh`
+- `git diff --check`
+
+No environmental limitation affected validation; checks ran on Linux/amd64.
+
 ## Stage 6 — Integrate direct underlays and their strict groups
 
 1. Thread state through acquireUnderlayGroup/grouped assembly. Direct underlays