fix(web): preserve JSON identity and coverage contracts

Decode base64 JSON body bytes at the shape owner without replacement characters. Keep incomplete request correspondence unknown and use explicitly complete authored inventories for positive comparison controls. Repair semantic truncation and storage fixtures to satisfy their owning contracts without weakening assertions.

src/domain/javascript/javascriptSemanticGraphQuery.test.ts

@@ -51,8 +51,15 @@ it.each(["unknown", "unavailable", "partial"] as const)(
           truncated: true,
           limits: [{ name: "nodes", value: 1, unit: "items" }],
         },
+        limitations: [
+          "Authored truncation tests status and omission coupling.",
+        ],
       }),
-    ).toThrow(/Truncated semantic graph coverage/u);
+    ).toThrow(
+      status === "partial"
+        ? "Truncated semantic graph coverage must acknowledge omitted facts"
+        : "Truncated semantic graph coverage must be partial",
+    );
   },
 );
 
@@ -69,6 +76,7 @@ it("accepts truncated partial coverage with unknown omission extents", () => {
         omitted_relations: null,
         limits: [{ name: "nodes", value: 1, unit: "items" }],
       },
+      limitations: ["Node ceiling left semantic omission extents unknown."],
     }).coverage,
   ).toMatchObject({ status: "partial", truncated: true });
 });
@@ -92,6 +100,7 @@ it("accepts omitted unknown occurrences as the reason for semantic truncation",
           : coverage,
       ),
     },
+    limitations: ["Unknown ceiling omitted one resource-limit occurrence."],
   });
   expect(graph.coverage).toMatchObject({
     truncated: true,