三维设置加箭头阈值，静默处理网格冲突

对话框写回 flow_on_px（二维三维共用），去掉 analysis_grid_mismatch 告警，缩短 UV/形变等工程腔文案并认 source=analysis。已用 pane UI 与 controller 单测验证。

apps/studio/tests/test_replay_analysis.py

@@ -978,10 +978,45 @@ def test_the_controller_redraws_on_a_display_change_and_runs_no_pass(pass_root):
         assert session.threshold() == pytest.approx(0.5)
         # The frame is rebuilt from the same stored record, not from a new one.
         assert session.frame(int(session.frame_ids[0])).frame_id == FIRST_FRAME_ID
+        assert host.notes == [], "a threshold change must not lecture about the grid"
     finally:
         session.reader.close()
 
 
+def test_a_refused_grid_change_redraws_without_a_status_warning():
+    """Moving max_arrows cannot be served; the frame is redrawn and nothing is said.
+
+    No evidence recording: the session is a stub whose ``serve_policy`` refuses, which
+    is exactly the path that used to push ``playback.analysis_grid_mismatch``.
+    """
+    class _Reader:
+        def close(self) -> None:
+            pass
+
+    class _Session:
+        def __init__(self) -> None:
+            self.calls: list = []
+            self.reader = _Reader()
+
+        def serve_policy(self, policy) -> bool:
+            self.calls.append(policy)
+            return False
+
+        def close(self) -> None:
+            pass
+
+    controller, host, engine, parts = _controller()
+    session = _Session()
+    controller.results.open_session(session)  # type: ignore[arg-type]
+    engine.use_analysis(session)
+    engine.redraws = 0
+    controller.on_display_settings(DisplaySettings(max_arrows=50))
+    assert engine.redraws == 1, "the refused policy still redraws the stored frame"
+    assert len(session.calls) == 1
+    assert host.notes == [], "a grid mismatch must not reach the status bar"
+    controller.results.close()
+
+
 # ------------------------------------------------------------ analysis on open
 def test_a_running_session_does_not_hide_a_stored_result(pass_root):
     """A result on disk is served while a session is open: reading it opens no chain.