fix(web): make first wasm load work on remote deployment

- Correct engine-manifest single wasm SHA and reuse cache for verification.
- Remove duplicate main-thread wasm fetch; raise init timeout to 300s.
- Record production deployment details and verification evidence.

Co-Authored-By: Claude Code <noreply@anthropic.com>

web/protocol/manifest.ts

@@ -262,7 +262,9 @@ export async function loadWebEngineManifest(url = "/engine-manifest.json"): Prom
 export async function verifyWasmResource(
   resource: Pick<WasmResource, "url" | "sha256"> & Partial<Pick<WasmResource, "id">>,
 ): Promise<void> {
-  const response = await fetch(resource.url, { cache: "no-store" });
+  // Reuse the HTTP cache populated by the worker's module loader. A no-store
+  // verification fetch would download the multi-hundred-MB engine wasm twice.
+  const response = await fetch(resource.url, { cache: "force-cache" });
   const resourceId = resource.id ?? resource.url;
   if (!response.ok) throw new Error(`WASM resource request failed: ${resourceId}`);
   const bytes = await response.arrayBuffer();