Agent: repair malformed tool calls and session files

src/agents/session-tool-result-guard.test.ts

@@ -141,4 +141,21 @@ describe("installSessionToolResultGuard", () => {
       .map((e) => (e as { message: AgentMessage }).message);
     expect(messages.map((m) => m.role)).toEqual(["assistant", "toolResult"]);
   });
+
+  it("drops malformed tool calls missing input before persistence", () => {
+    const sm = SessionManager.inMemory();
+    installSessionToolResultGuard(sm);
+
+    sm.appendMessage({
+      role: "assistant",
+      content: [{ type: "toolCall", id: "call_1", name: "read" }],
+    } as AgentMessage);
+
+    const messages = sm
+      .getEntries()
+      .filter((e) => e.type === "message")
+      .map((e) => (e as { message: AgentMessage }).message);
+
+    expect(messages).toHaveLength(0);
+  });
 });