various fix

backend/tests/test_algo_host_batch.py

@@ -266,6 +266,32 @@ def test_build_visualization_command_uses_hand_model_and_result_tsv(
     assert cmd[cmd.index("--max-width") + 1] == str(VISUALIZATION_MAX_WIDTH)
 
 
+def test_build_visualization_command_passes_font_path_when_available(
+    monkeypatch: pytest.MonkeyPatch,
+    tmp_path: Path,
+) -> None:
+    bundle = tmp_path / "bundle"
+    write_minimal_reference_bundle(bundle)
+    (bundle / "weights").mkdir()
+    (bundle / "weights" / "hand_detect.pt").write_bytes(b"fake")
+    (bundle / "visualize_result_video.py").write_text("# fake\n", encoding="utf-8")
+    font = tmp_path / "NotoSansCJK-Regular.ttc"
+    font.write_bytes(b"fake-font")
+    monkeypatch.setattr(
+        "app.algo_host.subprocess_runner.resolve_cjk_font_path",
+        lambda: font,
+    )
+
+    cmd = build_visualization_command(
+        bundle_dir=bundle,
+        video_path=tmp_path / "input.mp4",
+        result_path=tmp_path / "result.tsv",
+        output_video_path=tmp_path / "result_vis.mp4",
+    )
+
+    assert cmd[cmd.index("--font-path") + 1] == str(font)
+
+
 def test_build_batch_main_command_uses_5_15_main_py(tmp_path: Path) -> None:
     cmd = build_batch_main_command(
         bundle_dir=tmp_path / "algorithm_subprocesses" / "5.15",