test(cli): assert retained entropy Evidence beside the cleanup diagnostic

Check the partial observation returned with the close-failure diagnostic: provider id, file digest and byte count.

Refs #7279

Co-Authored-By: gensokyo-dev <gensokyo-dev@users.noreply.github.com>
Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

tests/process-global/byteEntropyCleanupCli.test.ts

@@ -1,3 +1,4 @@
+import { createHash } from "node:crypto";
 import { writeFile } from "node:fs/promises";
 import { join } from "node:path";
 import { afterEach, expect, it, vi } from "vitest";
@@ -72,7 +73,8 @@ it.each([
   async ({ closeFails, attempts }) => {
     const directory = await createTestTempDirectory("rea-entropy-cleanup-cli-");
     const path = join(directory, "entropy-input.bin");
-    await writeFile(path, "entropy fixture\n".repeat(32));
+    const content = Buffer.from("entropy fixture\n".repeat(32));
+    await writeFile(path, content);
     closeState.path = path;
     closeState.failures = closeFails ? Number.MAX_SAFE_INTEGER : 0;
 
@@ -91,6 +93,19 @@ it.each([
       details: {
         cleanup: "incomplete",
         diagnostics: {
+          primary_error: {
+            details: {
+              partial_observation: {
+                provider: { id: BYTE_ENTROPY_PROVIDER.id },
+                subject: {
+                  digest: {
+                    sha256: createHash("sha256").update(content).digest("hex"),
+                  },
+                },
+                normalized_result: { artifact: { bytes: content.length } },
+              },
+            },
+          },
           cleanup_error: {
             code: "cleanup_incomplete",
             details: { provider_id: BYTE_ENTROPY_PROVIDER.id },