H-391: preserve unknown cache state

Co-authored-by: multica-agent <github@multica.ai>

scripts/m0-spike.mjs

@@ -566,10 +566,10 @@ export function eventCollector(sessionId, targetId, {
             protocol: params.response.protocol,
             mime_type: params.response.mimeType,
             headers: redactHeaders(params.response.headers),
-            cache: {
+            cache: bodySources.has(requestId) ? {
               state: bodySources.get(requestId) === "network" ? "miss" : "hit",
               source: bodySources.get(requestId),
-            },
+            } : { state: "unknown" },
           },
         });
         break;
@@ -792,7 +792,10 @@ async function main(attemptFailures = [], startup = { requested_samples: 1, succ
     for (const pathname of ["/ok", "/secret", "/large", "/binary", "/secure"]) {
       await collectBody(cdp, collector, findRequest(collector.records, pathname), maxBodyBytes);
     }
-    const cachedId = findRequests(collector.records, "/cache").find((requestId) => collector.bodySources.get(requestId) !== "network");
+    const cachedId = findRequests(collector.records, "/cache").find((requestId) => {
+      const source = collector.bodySources.get(requestId);
+      return source && source !== "network";
+    });
     assert(cachedId, "a repeated force-cache request must be served from browser cache");
     await collectBody(cdp, collector, cachedId, maxBodyBytes);
     const failedId = [...collector.requestState.entries()].find(([, state]) => state.has("failed"))?.[0];