test: skip watermark integration when darktable export fails

Add darktable style probe and pytest integration/slow markers so CI and
machines without a working darktable-cli setup skip the full workflow test.

Co-authored-by: Cursor <cursoragent@cursor.com>

tests/test_workflow_modules.py

@@ -5,7 +5,6 @@ from pathlib import Path
 
 import pytest
 
-from imagepipeline.core.params import validate_params
 from imagepipeline.modules.color_to_alpha import (
     ColorToAlphaModule,
     build_color_to_alpha_args,
@@ -13,18 +12,19 @@ from imagepipeline.modules.color_to_alpha import (
 from imagepipeline.modules.composite import CompositeModule
 from imagepipeline.modules.crop_square import CropSquareModule
 from imagepipeline.modules.darktable_style import DarktableStyleModule
+from imagepipeline.modules.gmic_grayscale import GmicGrayscale
 from imagepipeline.modules.imagemagick_fill import (
     ImageMagickFillModule,
     build_fill_arguments,
 )
-from imagepipeline.modules.imagemagick_grayscale import ImageMagickGrayscale
 from imagepipeline.modules.imagemagick_resize import (
     ImageMagickResizeModule,
     build_resize_arguments,
 )
-from imagepipeline.modules.gmic_grayscale import GmicGrayscale
 from imagepipeline.modules.registry import get_module, list_modules
 from imagepipeline.modules.rembg import RembgModule
+from tests.integration_helpers import has_darktable_style
+from tests.integration_helpers import has_workflow_tools as check_workflow_tools
 
 has_magick = bool(shutil.which("magick") or shutil.which("convert"))
 
@@ -184,7 +184,6 @@ class TestImageMagickFill:
     def test_output_matches_input_size(self, tmp_path: Path) -> None:
         from imagepipeline.core.context import ModuleContext
         from imagepipeline.utils.subprocess import run_command
-
         from tests.conftest import make_png
 
         src = tmp_path / "ref.png"
@@ -221,7 +220,6 @@ class TestCropSquare:
     def test_center_crops_to_square(self, tmp_path: Path) -> None:
         from imagepipeline.core.context import ModuleContext
         from imagepipeline.utils.subprocess import run_command
-
         from tests.conftest import make_png
 
         src = tmp_path / "wide.png"
@@ -255,9 +253,7 @@ class TestModuleParameters:
             DarktableStyleModule.validate_module_params({})
 
     def test_darktable_style_accepts_style(self) -> None:
-        params = DarktableStyleModule.validate_module_params(
-            {"style": "Watermark F12.rocks"}
-        )
+        params = DarktableStyleModule.validate_module_params({"style": "Watermark F12.rocks"})
         assert params["style"] == "Watermark F12.rocks"
         assert params["style_overwrite"] is True
 
@@ -273,9 +269,7 @@ class TestModuleParameters:
     def test_darktable_export_conf_jpeg(self) -> None:
         from imagepipeline.modules.darktable_style import export_conf_options
 
-        assert export_conf_options("jpeg") == [
-            "plugins/imageio/format/jpeg/quality=90"
-        ]
+        assert export_conf_options("jpeg") == ["plugins/imageio/format/jpeg/quality=90"]
 
     def test_darktable_export_conf_png(self) -> None:
         from imagepipeline.modules.darktable_style import export_conf_options
@@ -308,7 +302,6 @@ class TestCompositeColor:
     def test_preserves_color_over_grayscale_background(self, tmp_path: Path) -> None:
         from imagepipeline.core.context import ModuleContext
         from imagepipeline.utils.subprocess import run_command
-
         from tests.conftest import make_png
 
         src = tmp_path / "src.png"
@@ -347,19 +340,20 @@ class TestCompositeColor:
 
         output = output_dir / "fg.png"
         assert output.is_file()
-        result = run_command(
-            [magick, "identify", "-format", "%[type]", str(output)]
-        )
+        result = run_command([magick, "identify", "-format", "%[type]", str(output)])
         assert result.stdout.strip() != "Grayscale"
 
 
-has_workflow_tools = all(
-    shutil.which(name)
-    for name in ("rembg", "gmic", "magick", "darktable-cli")
-) or all(shutil.which(name) for name in ("rembg", "gmic", "convert", "darktable-cli"))
+has_workflow_tools = check_workflow_tools()
 
 
+@pytest.mark.integration
+@pytest.mark.slow
 @pytest.mark.skipif(not has_workflow_tools, reason="Workflow CLI tools not installed")
+@pytest.mark.skipif(
+    not has_darktable_style("Watermark F12.rocks"),
+    reason="darktable style 'Watermark F12.rocks' not available or darktable-cli export failed",
+)
 class TestWorkflowIntegration:
     def test_watermark_pipeline(self, input_dir, output_base) -> None:
         from imagepipeline import Pipeline