fix: preserve archive on unlink failure

tools/select-manifest.mjs

@@ -33,8 +33,10 @@ export async function archiveManifest({ root = process.cwd(), network, now = new
   try {
     await operations.rm(source);
   } catch (error) {
-    await operations.rm(target, { force: true }).catch(() => {});
-    throw error;
+    throw new Error(
+      `archive created at ${target}, but source ${source} could not be removed; both paths were preserved: ${error.message}`,
+      { cause: error },
+    );
   }
   return { source, path: target };
 }

tools/test-base-config.sh

@@ -231,6 +231,28 @@ try {
   );
   assert.deepEqual(await readFile(canonicalPath), canonicalBytes);
   assert.deepEqual(await readFile(boundaryPath), boundaryBytes);
+
+  const unlinkFailureDate = new Date("2026-08-21T12:37:56.789Z");
+  const unlinkFailurePath = join(deployments, "base-sepolia.20260821T123756789Z.json");
+  await assert.rejects(
+    () => archiveManifest({
+      root,
+      network: "baseSepolia",
+      now: unlinkFailureDate,
+      io: {
+        rm: async (path, options) => {
+          if (path === canonicalPath) {
+            assert.deepEqual(await readFile(unlinkFailurePath), canonicalBytes);
+            throw new Error("source unlink failed");
+          }
+          return rm(path, options);
+        },
+      },
+    }),
+    /source unlink failed/,
+  );
+  assert.deepEqual(await readFile(canonicalPath), canonicalBytes);
+  assert.deepEqual(await readFile(unlinkFailurePath), canonicalBytes);
   await assert.rejects(() => archiveManifest({ root, network: "anvil" }), /baseSepolia/);
 } finally {
   await rm(root, { recursive: true, force: true });