fix(javascript): preserve semantic gaps for unparseable sources

Successful worker transport can carry an explicit failed parser status
with no semantic projection. Preserve that producer fact through the
shared source-availability interpretation used by full and incremental
graph construction, rather than dropping the source's semantic scope.

Retain the module when capacity permits, per-family incomplete-module
unknowns, and unknown omitted extents. Preserve existing operational
failure reasons and limits without classifying syntax as resource loss.
Document this coverage behavior.

Validation: regression-first run had 3 expected failures; all 22 selected
projection and public CLI source-selection/HTML cases passed after repair.
No JavaScript target execution or live external provider was involved.

src/domain/javascript/javascriptArtifactFiles.ts

@@ -1,6 +1,7 @@
 import { z } from "zod";
 import { digestSchema } from "../digests.js";
 import type { JavaScriptSourceSelection } from "./javascriptSourceSelection.js";
+import type { JavaScriptStaticAnalysis } from "./javascriptStaticAnalysisTypes.js";
 import type {
   ArtifactInventoryCoverage,
   ArtifactOccurrence,
@@ -61,6 +62,20 @@ export const javaScriptArtifactTextExclusion = (
     : "Source bytes are not valid UTF-8; JavaScript semantics were not analyzed.";
 };
 
+/** Source availability shared by semantic consumers of parsed artifact facts. */
+export const javaScriptSemanticSourceExclusion = (
+  file: JavaScriptArtifactFile,
+  parseStatus: JavaScriptStaticAnalysis["parse_status"] | null,
+): string | null => {
+  if (file.kind !== "javascript") return null;
+  return (
+    javaScriptArtifactTextExclusion(file) ??
+    (parseStatus === "failed"
+      ? "JavaScript syntax could not be parsed; JavaScript semantics were not analyzed."
+      : null)
+  );
+};
+
 /**
  * One inventoried regular file not backed by analyzed source bytes. Its inventory
  * occurrence remains available even when content is opaque or unavailable.