Assemble imported sequence-item scopes

docs/config.md

@@ -884,6 +884,25 @@ walk failures, matched directories, invalid documents, escapes, and repeated tar
 remain errors. Final candidates are bounded by the remaining source limit before
 their contents are accumulated.
 
+Each path or glob declaration may include `placement: mapping` or
+`placement: sequence-item`. Omission means `mapping` for that declaration,
+including every match of a glob; placement is not inherited. Sequence-item
+placement requires a nonempty effective destination and wraps the imported
+mapping as one element of a sequence there. It does not split source sequences
+or enable sequence accumulation: overlapping sequences still follow the strict
+composition rules above.
+
+An item import first opens a local mapping scope. Its body and ordinary helper
+imports compose within that record. An omitted helper destination or
+`destination: []` places the helper at the record root; other destinations are
+relative to the immediate importing source. A helper may supply fields such as
+the record's `id`. An explicit nested `sequence-item` import creates a sequence
+inside the record, and its placement is independent of the enclosing item.
+At the record root, an item import must name a nonempty nested destination.
+Physical paths continue to resolve from the file that declares each import.
+An actual empty mapping contributes an empty item, while an optional unmatched
+path or glob contributes nothing.
+
 For host files, the configuration root defaults to the selected file's canonical
 directory. A host file may supply `FilesystemContext.Root` to widen that root but
 may not supply `BaseDir` or a native `FS`. Byte, reader, and mapping inputs with host context

docs/roadmap/implementation.md

@@ -1,6 +1,6 @@
 # Implementation Plan: Sequence Placement and Composition
 
-Status: implementation in progress; stages 1–7 completed.
+Status: implementation in progress; stages 1–8 completed.
 
 ## Purpose and authority
 
@@ -505,6 +505,20 @@ Validation: import/directive/glob/destination/composition tests and
 `./scripts/check.sh`. Completion: private item imports construct the agreed
 records and preserve physical acquisition evidence.
 
+Completion evidence: import declarations now parse per-declaration placement,
+and item imports compose their body and ordinary helpers in a local mapping
+scope before wrapping the completed record. Nested item scopes, glob matches,
+relative and transitive helper destinations, source origins/history, and
+resolved underlay destinations are retained. Configuration documentation
+describes only the implemented import-placement subset; private registration
+controls remain unadvertised. These checks passed with Go `go1.26.9 linux/amd64`:
+
+- `GOTOOLCHAIN=local GOPROXY=off go test ./internal/engine -run 'Import|Directive|Glob|Destination|Compose|NativeFilesystem' -count=1`
+- `GOTOOLCHAIN=local ./scripts/check.sh`
+- `git diff --check`
+
+No environmental limitation affected validation; checks ran on Linux/amd64.
+
 ## Stage 9 — Wire strict policy through the complete loading lifecycle
 
 Scope: ordinary/grouped engine loading and every strict-tier entry point.