Fix native health polling and isolate file operation traffic

tests/unit/native-hosts.test.ts

@@ -15,6 +15,24 @@ async function enrolled() {
 }
 
 describe('native host enrollment and scoped authentication', () => {
+    it('reserves health delivery while a file backlog is pending and bounds background batches', async () => {
+        const api = await enrolled();
+        api.heartbeat(api.host.id, { ...inventory, capabilities: ['operations.health-lane'] });
+        const files = Array.from({ length: 30 }, (_, i) => api.queueHostOperation(api.host.id, 'files.read', { path: `file-${i}` }));
+        const status = api.queueHostOperation(api.host.id, 'rcon.execute', { command: 'status' });
+        const inspect = api.queueHostOperation(api.host.id, 'instance.inspect', {});
+        const mutation = api.queueHostOperation(api.host.id, 'rcon.execute', { command: 'map_restart' });
+        expect(api.pendingHostOperations(api.host.id, 'health').map(op => op.id)).toEqual([status.id]);
+        api.reportHostOperation(api.host.id, status.id, { state: 'completed', result: {} });
+        expect(api.pendingHostOperations(api.host.id, 'health').map(op => op.id)).toEqual([inspect.id]);
+        expect(api.pendingHostOperations(api.host.id, 'read').map(op => op.id)).toEqual(files.slice(0, 4).map(op => op.id));
+        expect(api.pendingHostOperations(api.host.id, 'write').map(op => op.id)).toEqual([mutation.id]);
+        // Rolling upgrades: older agents still receive health through read.
+        api.heartbeat(api.host.id, inventory);
+        files.forEach(file => api.reportHostOperation(api.host.id, file.id, { state: 'completed', result: {} }));
+        expect(api.pendingHostOperations(api.host.id, 'read').map(op => op.id)).toEqual([inspect.id]);
+    });
+
     it('separates observation and mutation delivery and wakes long polls on newly queued work', async () => {
         const api = await enrolled();
         const inspect = api.queueHostOperation(api.host.id, 'host.inspect', {});