Compact screenshot context every 4 steps by default

tests/test_server_api.py

@@ -27,6 +27,7 @@ class FakeJobManager:
         type_interval: float = 0.02,
         click_pause: float = 0.10,
         reasoning_effort: str = "medium",
+        screen_context_decay_steps: int = 4,
         disabled_tools: list[str] | None = None,
         safety_override: bool = False,
         no_failsafe: bool = False,
@@ -48,6 +49,7 @@ class FakeJobManager:
             "type_interval": type_interval,
             "click_pause": click_pause,
             "reasoning_effort": reasoning_effort,
+            "screen_context_decay_steps": screen_context_decay_steps,
             "no_failsafe": no_failsafe,
         }
         self._jobs[job_id] = {
@@ -192,6 +194,7 @@ def test_create_job_returns_only_job_id_and_defaults_model(tmp_path: Path, monke
     assert manager.last_submit_payload["model"] == "gpt-5.4-mini"
     assert manager.last_submit_payload["disabled_tools"] == ["click"]
     assert manager.last_submit_payload["reasoning_effort"] == "medium"
+    assert manager.last_submit_payload["screen_context_decay_steps"] == 4
 
     status_res = client.get(f"/api/jobs/{job_id}/status", headers=headers)
     assert status_res.status_code == 200