fix(javascript): preserve graph facts across omissions and versions

Omit absent inventory facts without erasing explicit unknowns. Compare canonical file occurrences by source path and digest while preserving complete container provenance in observations and Evidence.

Consolidate candidate-capacity fixtures around unresolved alternatives and update inventory coverage and source-occurrence oracles. Preserve resource, identity, relationship uncertainty, cancellation, and transfer regressions.

src/application/javascript/JavaScriptArtifactGraphStructure.ts

@@ -390,8 +390,12 @@ const addUnavailableArtifactEntries = (
             ...(file.inventory_occurrence_id === undefined
               ? {}
               : { inventory_occurrence_id: file.inventory_occurrence_id }),
-            hash_status: file.hash_status,
-            artifact_kind: file.artifact_kind,
+            ...(file.hash_status === undefined
+              ? {}
+              : { hash_status: file.hash_status }),
+            ...(file.artifact_kind === undefined
+              ? {}
+              : { artifact_kind: file.artifact_kind }),
             ...(file.kind === undefined ? {} : { kind: file.kind }),
             content_available: false,
           },
@@ -414,7 +418,9 @@ const addUnavailableArtifactEntries = (
       properties: {
         path: file.path,
         content_available: false,
-        hash_status: file.hash_status,
+        ...(file.hash_status === undefined
+          ? {}
+          : { hash_status: file.hash_status }),
       },
       evidence: artifactObservationEvidence({
         sha256: file.container_sha256,