Agent: durable turn and queue state, visible inbox closure, OpenAI phase; prompt fixes; fetch/bench fixes

examples/bench/src/main.rs

@@ -10,6 +10,10 @@ fn main() {
         }
         let target = message.body["target"].as_str().unwrap_or("echo");
         let n = message.body["n"].as_u64().unwrap_or(1000);
+        if n == 0 {
+            let _ = reply(&message, json!({"type": "error", "reason": "n must be greater than 0"}));
+            continue;
+        }
         let mut times = Vec::new();
         let started = Instant::now();
         for i in 0..n {

examples/bench/tests/zero.json

@@ -0,0 +1,9 @@
+{
+  "description": "reject zero benchmark samples",
+  "steps": [
+    {
+      "send": {"type": "bench", "n": 0},
+      "expect": {"type": "error", "reason": "n must be greater than 0"}
+    }
+  ]
+}