Unify layered provenance history

docs/roadmap/implementation.md

@@ -2,7 +2,7 @@
 
 ## Status and ownership
 
-Status: implementation in progress; Stages 1–13 are complete and later stages are
+Status: implementation in progress; Stages 1–14 are complete and later stages are
 pending.
 
 Audience: a `gpt-5.6-terra` coding agent implementing one stage per prompt, in
@@ -1038,7 +1038,31 @@ Acceptance:
 
 ## Stage 14 — Verify layered provenance and final snapshot agreement
 
-Status: pending.
+Status: complete.
+
+Completion evidence (2026-09-06):
+
+- Unified default, composed base, profile displacement, and resolution records in
+  the metadata history index. Container resolution now appends its operation to each
+  changed, added, or removed descendant while preserving the ancestor operation path
+  and path-specific previous origin; effective metadata still contains only the final
+  projected paths.
+- Added a representative public `Load` workflow spanning a fresh default, selected
+  source, depth-first import, profile, derived default, mapping deletion, and
+  whole-sequence normalization. It verifies source order, equal-to-default
+  explicitness, null state, composite empty-mapping origins, chronological parent
+  replacement history, deduplicated reasons/dependencies, typed/final snapshot
+  agreement, and unchanged siblings.
+- Verified nested metadata, source import locations, diagnostics, caller-owned
+  configuration, and private snapshots are detached. Repeated concurrent selected-
+  profile loads retain independent typed values, metadata, sources, and histories;
+  the race baseline passes.
+- Promoted layered metadata semantics and concrete composite/synthetic origin cases
+  to the [current metadata contract](../config.md#layered-metadata), updated Go
+  reference comments, and recorded the adapted Narratio ownership/inspection cases.
+  Rendering, redaction, value snapshots, and explanation remain within later stages.
+  Verified `go test ./...`, `go test -race ./...`, `go vet ./...`, `go build ./...`,
+  `go mod tidy -diff`, and `git diff --check` with Go 1.26.7 on linux/amd64.
 
 Read: feature [presence](initial.md#paths-and-presence),
 [history](initial.md#provenance-diagnostics-and-redaction), metadata API.

docs/roadmap/initial.md

@@ -430,23 +430,12 @@ conversion through the current loading lifecycle.
 
 ## Paths and presence
 
-Semantic path construction, JSON Pointer parsing, and base/default metadata
-population are implemented. Their current contracts are owned by the Go
+Semantic path construction, JSON Pointer parsing, and layered metadata population
+are implemented. Their current contracts are owned by the Go
 documentation in [`path.go`](../../path.go), [`metadata.go`](../../metadata.go),
-and the [current configuration contract](../config.md#base-default-metadata).
-Layered replacement and resolution behavior below remains target lifecycle work.
-
-Distinguish absent, explicitly null, explicitly zero/false/empty, and other
-explicit values. An explicit value equal to its default remains explicit.
-Presence queries describe the surviving input contribution after overlays;
-separate history queries describe earlier appearances. A parent mapping's
-presence does not make all of its children explicit. Replacing a subtree removes
-its descendants from effective presence and origin queries while retaining
-historical replacement records.
-
-Application normalization preserves the fact that a surviving input was
-explicit. A derived value for an absent input remains non-explicit. Its final
-origin is a resolution operation, with input origins retained separately.
+and the [current metadata contract](../config.md#layered-metadata), including
+presence, composite origins, parent replacements, removed-path history, and
+synthetic resolution operations.
 
 ## Composition and overlay
 
@@ -481,8 +470,7 @@ The [current application schema contract](../config.md#application-schema-bindin
 owns root/type support, field and tag binding, inlining, codec pairing, and
 schema-aware path rules. The [current defaults and typed-decoding contract](../config.md#defaults-and-typed-decoding)
 owns strict conversions, container application, presence, safe failures, and initial
-origins. Public lifecycle integration, layered provenance, secret handling, and
-rendering remain target work below.
+origins. Secret handling and rendering remain target work below.
 
 ## Recorded resolution and validation
 
@@ -490,7 +478,8 @@ Application-owned recorded resolution is implemented. The
 [current resolution contract](../config.md#recorded-application-resolution) owns
 explicitness queries, helpers and manual records, structural mutation auditing,
 coalescing, diagnostics, origins, history, and snapshot ownership. Layered input
-history, redacted explanation, and secret dependency propagation remain target work.
+history is owned by the [current metadata contract](../config.md#layered-metadata);
+redacted explanation and secret dependency propagation remain target work.
 
 Canonical typed projection, detached cloning, structural comparison, and publishing
 independently captured resolved results are implemented. The
@@ -507,16 +496,10 @@ callback lifetime, and application/runtime responsibility boundaries.
 Safe diagnostic/provenance value records, canonical diagnostic rendering, and
 `LoadError` access are implemented. Their current contracts are owned by
 [`records.go`](../../records.go) and [`diagnostic.go`](../../diagnostic.go).
-Base/default and resolution records are attached to the current loading lifecycle.
-Additional layers, safe historical values, redaction, and rendering remain target
-work below.
-
-Retain input sources, layer, line/column where available, import sites, effective
-origins, overridden definition records, and resolution operations. Container
-origins may be composite; never invent one file location for a mapping assembled
-from several sources. Defaults and resolution have synthetic origins rather
-than fabricated file coordinates. Preserve definition history without exposing
-mutable parser nodes or unrestricted raw value references through the API.
+Default, base, profile, and resolution records are attached to the loading lifecycle;
+their source ordering, composite/synthetic origins, replacement history, and detached
+queries are owned by the [current metadata contract](../config.md#layered-metadata).
+Safe historical values, redaction, and rendering remain target work below.
 
 Diagnostics have stable codes, severity, semantic path when available, a safe
 message, primary location, and related locations. Sort deterministically by
@@ -697,11 +680,11 @@ func ReadWorkerDefaults() (*configkit.Result[Config], error) {
 
 ### Paths and metadata
 
-The path API, detached metadata records, empty/unknown query behavior, and
-base/default population are now implemented; [`path.go`](../../path.go),
+The path API, detached metadata records, empty/unknown query behavior, and layered
+population are implemented; [`path.go`](../../path.go),
 [`records.go`](../../records.go), [`metadata.go`](../../metadata.go), and the
-[metadata configuration contract](../config.md#base-default-metadata) own current
-behavior. Layered callback history and safe historical values remain target behavior.
+[metadata configuration contract](../config.md#layered-metadata) own current
+behavior. Safe historical values remain target behavior for explanation.
 
 ### Resolution and validation callbacks