Record input destination decision and baseline

docs/roadmap/implementation.md

@@ -123,7 +123,7 @@ completion evidence. Planning baseline: `6353598`.
 
 ## Stage 1 — Record the decision and capture the baseline
 
-Status: planned. Scope: decision record and evidence, no feature code.
+Status: complete. Scope: decision record and evidence, no feature code.
 
 1. Read the roadmap, request, relevant policies, and ADRs 0001, 0003, 0006,
    0008, and 0009. Inspect the owners identified in the roadmap and the function
@@ -142,8 +142,40 @@ Status: planned. Scope: decision record and evidence, no feature code.
    as minor-release work; select a version and write its note only during
    separately authorized release preparation.
 
-Validate: local-link test and whitespace checks. Done: baseline evidence and
-the decision are recorded; implemented contracts remain unchanged.
+Validated: `./scripts/check.sh` (go1.26.8 linux/amd64) passed on candidate
+`d3d468a8b47d780787fca329ff65b107d98ca59f`; this includes formatting,
+whitespace, local documentation links, tests, vet, and build. The planning
+baseline `6353598bd6cce2eb78a5fe990e144cc0cadf1280` is present in history. The
+worktree was clean before this stage.
+
+Coverage located for later destination work:
+
+- Root and equivalent source loading: `TestEquivalentSourceFormsPreserveInputSemantics`
+  (`facade_equivalence_test.go`) and
+  `TestFacadeLayeredZeroUnderlaysMatchesOrdinaryLoad` (`facade_layered_test.go`).
+- Strict underlays and group budgets: `TestGroupedLoadStrictConflictsRepetitionAndBudgets`
+  and `TestGroupedLoadPrecedenceSourceOrderAndSingleLifecycle`
+  (`internal/engine/load_request_test.go`).
+- Version ownership and imported claims: `TestLoadRejectsImportConflictsAndFragmentVersions`
+  (`internal/engine/imports_test.go`) and version-path coverage in
+  `internal/engine/load_test.go`.
+- Repeated physical sources: `TestRepeatedImportsAcrossTiersAndReaderConsumption`
+  (`facade_equivalence_test.go`).
+- History and source contexts: `TestUnderlayHistoryRetainsLaterMappingContributors`
+  (`facade_underlay_origins_test.go`) and
+  `TestFacadeSourceContextsFollowOriginsWithoutQueryIO`
+  (`facade_resource_context_test.go`).
+- Detached records: `TestLoadMetadataReflectsDefaultsInputAndDetachedRecords`
+  (`internal/engine/load_test.go`) and
+  `TestMetadataQueriesReturnDetachedRecords` (`internal/engine/metadata_test.go`).
+
+The decision is recorded in [ADR 0011](../adr/0011-input-destinations.md).
+Compatibility assessment: adding the two public fields breaks callers using
+unkeyed literals for `Input` or `SourceInfo`; keyed and zero-value use remains
+compatible. The release policy permits the intentional pre-1.0 contract change
+in a minor release when the release note states impact and migration. Version
+selection and release-note preparation remain out of scope until separately
+authorized. No feature code or current behavior contract changed.
 
 ## Stage 2 — Add private destination normalization and wrapping