diff --git a/apps/worker/video_processing/cover_generator.py b/apps/worker/video_processing/cover_generator.py
index b2cc5bad3..8e656e6d2 100755
--- a/apps/worker/video_processing/cover_generator.py
+++ b/apps/worker/video_processing/cover_generator.py
@@ -93,20 +93,23 @@ class CoverGenerator:
             time_sec = 0
 
         # scale + crop 实现 cover 裁剪（铺满输出尺寸）
-        vf = (
-            f"scale={width}:{height}:force_original_aspect_ratio=increase,"
-            f"crop={width}:{height}"
-        )
+        vf = f"scale={width}:{height}:force_original_aspect_ratio=increase," f"crop={width}:{height}"
 
         command = [
             FFMPEG_BIN,
             "-y",
-            "-ss", f"{time_sec:.3f}",
-            "-i", str(video_path),
-            "-vframes", "1",
-            "-vf", vf,
-            "-q:v", str(quality),
-            "-f", "mjpeg",
+            "-ss",
+            f"{time_sec:.3f}",
+            "-i",
+            str(video_path),
+            "-vframes",
+            "1",
+            "-vf",
+            vf,
+            "-q:v",
+            str(quality),
+            "-f",
+            "mjpeg",
             str(output_path),
         ]
 
@@ -159,9 +162,12 @@ class CoverGenerator:
         if duration <= 0 or frame_count <= 1:
             # 无法获取时长或只有1帧，退化为普通抽帧
             return CoverGenerator.extract_frame(
-                video_path, output_path,
+                video_path,
+                output_path,
                 time_sec=min(DEFAULT_COVER_TIME, max(0, duration / 2)),
-                width=width, height=height, quality=quality,
+                width=width,
+                height=height,
+                quality=quality,
             )
 
         # 临时目录
@@ -185,9 +191,12 @@ class CoverGenerator:
             frame_path = work_dir / f"cover_candidate_{i}.jpg"
             try:
                 CoverGenerator.extract_frame(
-                    video_path, frame_path,
+                    video_path,
+                    frame_path,
                     time_sec=t,
-                    width=width, height=height, quality=quality,
+                    width=width,
+                    height=height,
+                    quality=quality,
                 )
                 candidate_frames.append((t, frame_path))
             except Exception as e:
@@ -198,14 +207,18 @@ class CoverGenerator:
             # 全部失败，退化到普通抽帧
             logger.warning("智能封面所有候选帧抽取失败，退化为普通抽帧")
             return CoverGenerator.extract_frame(
-                video_path, output_path,
+                video_path,
+                output_path,
                 time_sec=min(DEFAULT_COVER_TIME, duration / 2),
-                width=width, height=height, quality=quality,
+                width=width,
+                height=height,
+                quality=quality,
             )
 
         if len(candidate_frames) == 1:
             # 只有一帧，直接用
             import shutil
+
             shutil.copy2(candidate_frames[0][1], output_path)
             return output_path
 
@@ -217,11 +230,14 @@ class CoverGenerator:
 
         # 复制最佳帧到输出路径
         import shutil
+
         shutil.copy2(best_frame[1], output_path)
 
         logger.info(
             "智能封面生成完成: 候选%d帧, 最佳t=%.2fs, 大小=%d字节",
-            len(candidate_frames), best_frame[0], output_path.stat().st_size,
+            len(candidate_frames),
+            best_frame[0],
+            output_path.stat().st_size,
         )
 
         # 清理临时文件
@@ -265,18 +281,19 @@ class CoverGenerator:
         output_path.parent.mkdir(parents=True, exist_ok=True)
 
         # scale + crop 实现 cover 裁剪
-        vf = (
-            f"scale={width}:{height}:force_original_aspect_ratio=increase,"
-            f"crop={width}:{height}"
-        )
+        vf = f"scale={width}:{height}:force_original_aspect_ratio=increase," f"crop={width}:{height}"
 
         command = [
             FFMPEG_BIN,
             "-y",
-            "-i", str(image_path),
-            "-vf", vf,
-            "-q:v", str(quality),
-            "-f", "mjpeg",
+            "-i",
+            str(image_path),
+            "-vf",
+            vf,
+            "-q:v",
+            str(quality),
+            "-f",
+            "mjpeg",
             str(output_path),
         ]
 
@@ -288,6 +305,7 @@ class CoverGenerator:
             # 处理失败，直接复制原图
             logger.warning("自定义封面处理失败，使用原图")
             import shutil
+
             shutil.copy2(image_path, output_path)
 
         return output_path
@@ -321,20 +339,29 @@ class CoverGenerator:
         """
         if mode == "custom" and custom_image:
             return CoverGenerator.process_custom_cover(
-                custom_image, output_path,
-                width=width, height=height, quality=quality,
+                custom_image,
+                output_path,
+                width=width,
+                height=height,
+                quality=quality,
             )
         elif mode == "time":
             return CoverGenerator.extract_frame(
-                video_path, output_path,
+                video_path,
+                output_path,
                 time_sec=time_sec,
-                width=width, height=height, quality=quality,
+                width=width,
+                height=height,
+                quality=quality,
             )
         else:
             # 默认智能封面
             return CoverGenerator.extract_smart_cover(
-                video_path, output_path,
-                width=width, height=height, quality=quality,
+                video_path,
+                output_path,
+                width=width,
+                height=height,
+                quality=quality,
             )
 
 
@@ -379,7 +406,8 @@ def generate_cover_from_plan(
             custom_path = cover_config.get("custom_image_path")
             if custom_path and Path(custom_path).exists():
                 return CoverGenerator.process_custom_cover(
-                    custom_path, output_path,
+                    custom_path,
+                    output_path,
                 )
             else:
                 logger.warning("自定义封面图片路径无效，退化为智能封面")
@@ -388,12 +416,15 @@ def generate_cover_from_plan(
         if mode == "time":
             time_sec = float(cover_config.get("time_sec", DEFAULT_COVER_TIME))
             return CoverGenerator.extract_frame(
-                video_path, output_path, time_sec=time_sec,
+                video_path,
+                output_path,
+                time_sec=time_sec,
             )
         else:
             # smart
             return CoverGenerator.extract_smart_cover(
-                video_path, output_path,
+                video_path,
+                output_path,
             )
     except Exception as e:
         logger.warning("封面生成失败: %s", e)
diff --git a/apps/worker/video_processing/render_audio.py b/apps/worker/video_processing/render_audio.py
index 20ec7a698..59246be1f 100755
--- a/apps/worker/video_processing/render_audio.py
+++ b/apps/worker/video_processing/render_audio.py
@@ -156,9 +156,7 @@ def concat_main_audio(
         reverse_config = ReverseConfig.from_dict(clip.config.get("reverse"))
         af_filters = []
         if reverse_config.enabled and reverse_config.reverse_audio:
-            reverse_filter = ReverseEngine.build_audio_filter(
-                reverse_config, duration=effective_duration
-            )
+            reverse_filter = ReverseEngine.build_audio_filter(reverse_config, duration=effective_duration)
             if reverse_filter:
                 af_filters.append(reverse_filter)
 
@@ -198,9 +196,7 @@ def concat_main_audio(
         # 音频倒放
         reverse_config = ReverseConfig.from_dict(clip.config.get("reverse"))
         if reverse_config.enabled and reverse_config.reverse_audio:
-            reverse_filter = ReverseEngine.build_audio_filter(
-                reverse_config, duration=effective_duration
-            )
+            reverse_filter = ReverseEngine.build_audio_filter(reverse_config, duration=effective_duration)
             if reverse_filter:
                 audio_filters.append(reverse_filter)
 
diff --git a/apps/worker/video_processing/reverse_engine.py b/apps/worker/video_processing/reverse_engine.py
index e21128bf8..d72322534 100755
--- a/apps/worker/video_processing/reverse_engine.py
+++ b/apps/worker/video_processing/reverse_engine.py
@@ -27,8 +27,8 @@ class ReverseConfig:
     """
 
     enabled: bool = False
-    reverse_video: bool = True   # 是否倒放视频
-    reverse_audio: bool = True   # 是否倒放音频
+    reverse_video: bool = True  # 是否倒放视频
+    reverse_audio: bool = True  # 是否倒放音频
 
     @classmethod
     def from_dict(cls, data: dict[str, Any] | None) -> "ReverseConfig":
diff --git a/apps/worker/video_processing/sticker_engine.py b/apps/worker/video_processing/sticker_engine.py
index 86fc8e8c1..0cb4068c9 100755
--- a/apps/worker/video_processing/sticker_engine.py
+++ b/apps/worker/video_processing/sticker_engine.py
@@ -238,17 +238,13 @@ class StickerEngine:
 
         # 贴纸预处理
         if pre_filters:
-            filter_parts.append(
-                f"[{sticker_idx + 1}:v]{','.join(pre_filters)}[{sticker_label}]"
-            )
+            filter_parts.append(f"[{sticker_idx + 1}:v]{','.join(pre_filters)}[{sticker_label}]")
             sticker_source = f"[{sticker_label}]"
         else:
             sticker_source = f"[{sticker_idx + 1}:v]"
 
         # overlay 合成
-        filter_parts.append(
-            f"{input_label}{sticker_source}overlay={pos_x:.0f}:{pos_y:.0f}{enable_expr}{output_label}"
-        )
+        filter_parts.append(f"{input_label}{sticker_source}overlay={pos_x:.0f}:{pos_y:.0f}{enable_expr}{output_label}")
 
         return ";".join(filter_parts)
 
@@ -308,9 +304,7 @@ class StickerEngine:
 
         # 时间范围
         if sticker.duration > 0:
-            drawtext_params.append(
-                f"enable='between(t,{sticker.start_time},{sticker.start_time + sticker.duration})'"
-            )
+            drawtext_params.append(f"enable='between(t,{sticker.start_time},{sticker.start_time + sticker.duration})'")
 
         # 淡入淡出（drawtext 没有直接的淡入淡出，用 alpha 表达式模拟）
         if sticker.fade_in > 0 or sticker.fade_out > 0:
@@ -318,14 +312,12 @@ class StickerEngine:
             parts: list[str] = []
             if sticker.fade_in > 0:
                 parts.append(
-                    f"if(lt(t,{sticker.start_time + sticker.fade_in}),"
-                    f"(t-{sticker.start_time})/{sticker.fade_in},1)"
+                    f"if(lt(t,{sticker.start_time + sticker.fade_in})," f"(t-{sticker.start_time})/{sticker.fade_in},1)"
                 )
             if sticker.fade_out > 0 and sticker.duration > 0:
                 fade_out_start = sticker.start_time + sticker.duration - sticker.fade_out
                 parts.append(
-                    f"if(gt(t,{fade_out_start}),"
-                    f"({sticker.start_time + sticker.duration}-t)/{sticker.fade_out},1)"
+                    f"if(gt(t,{fade_out_start})," f"({sticker.start_time + sticker.duration}-t)/{sticker.fade_out},1)"
                 )
             if parts:
                 alpha_expr = "*".join(parts)
@@ -522,15 +514,11 @@ class StickerEngine:
         # 淡入淡出（使用 fade 的 alpha 模式）
         fade_filters: list[str] = []
         if sticker.fade_in > 0:
-            fade_filters.append(
-                f"fade=in:st={sticker.start_time}:d={sticker.fade_in}:alpha=1"
-            )
+            fade_filters.append(f"fade=in:st={sticker.start_time}:d={sticker.fade_in}:alpha=1")
         if sticker.fade_out > 0 and sticker.duration > 0:
             fade_out_start = sticker.start_time + sticker.duration - sticker.fade_out
             if fade_out_start > 0:
-                fade_filters.append(
-                    f"fade=out:st={fade_out_start}:d={sticker.fade_out}:alpha=1"
-                )
+                fade_filters.append(f"fade=out:st={fade_out_start}:d={sticker.fade_out}:alpha=1")
 
         # 估算贴纸尺寸用于位置计算
         est_w = int(canvas_w * 0.3 * sticker.scale) if not sticker.width else sticker.width
@@ -540,26 +528,20 @@ class StickerEngine:
         # enable 表达式
         enable_expr = ""
         if sticker.duration > 0:
-            enable_expr = (
-                f":enable='between(t,{sticker.start_time},{sticker.start_time + sticker.duration})'"
-            )
+            enable_expr = f":enable='between(t,{sticker.start_time},{sticker.start_time + sticker.duration})'"
 
         parts: list[str] = []
 
         # 贴纸预处理
         all_pre = pre_filters + fade_filters
         if all_pre:
-            parts.append(
-                f"[{sticker_input_idx}:v]{','.join(all_pre)}[{scaled_label}]"
-            )
+            parts.append(f"[{sticker_input_idx}:v]{','.join(all_pre)}[{scaled_label}]")
             sticker_source = f"[{scaled_label}]"
         else:
             sticker_source = f"[{sticker_input_idx}:v]"
 
         # overlay 合成
-        parts.append(
-            f"{input_label}{sticker_source}overlay={pos_x:.0f}:{pos_y:.0f}{enable_expr}{output_label}"
-        )
+        parts.append(f"{input_label}{sticker_source}overlay={pos_x:.0f}:{pos_y:.0f}{enable_expr}{output_label}")
 
         return ";".join(parts)
 
diff --git a/apps/worker/video_processing/unified_render_service.py b/apps/worker/video_processing/unified_render_service.py
index 00d7070d5..128e4165f 100755
--- a/apps/worker/video_processing/unified_render_service.py
+++ b/apps/worker/video_processing/unified_render_service.py
@@ -838,9 +838,7 @@ class UnifiedRenderService:
         # 倒放滤镜
         reverse_config = ReverseConfig.from_dict(clip.config.get("reverse"))
         if reverse_config.enabled and reverse_config.reverse_video:
-            reverse_filter = ReverseEngine.build_video_filter(
-                reverse_config, duration=effective_duration
-            )
+            reverse_filter = ReverseEngine.build_video_filter(reverse_config, duration=effective_duration)
             if reverse_filter:
                 filters.append(reverse_filter)
 
@@ -905,9 +903,7 @@ class UnifiedRenderService:
             # 音频倒放
             reverse_config = ReverseConfig.from_dict(clip.config.get("reverse"))
             if reverse_config.enabled and reverse_config.reverse_audio:
-                af_filter = ReverseEngine.build_audio_filter(
-                    reverse_config, duration=effective_duration
-                )
+                af_filter = ReverseEngine.build_audio_filter(reverse_config, duration=effective_duration)
                 if af_filter:
                     command.extend(["-af", af_filter])
 
@@ -1068,9 +1064,7 @@ class UnifiedRenderService:
             # 倒放滤镜（在 trim 之后、scale 之前应用）
             reverse_config = ReverseConfig.from_dict(clip.config.get("reverse"))
             if reverse_config.enabled and reverse_config.reverse_video:
-                reverse_filter = ReverseEngine.build_video_filter(
-                    reverse_config, duration=effective_duration
-                )
+                reverse_filter = ReverseEngine.build_video_filter(reverse_config, duration=effective_duration)
                 if reverse_filter:
                     filters.append(reverse_filter)
 
@@ -1240,9 +1234,7 @@ class UnifiedRenderService:
             )
             raise
 
-    def _build_sticker_filters(
-        self, input_label: str, output_label: str
-    ) -> tuple[str, list[str]]:
+    def _build_sticker_filters(self, input_label: str, output_label: str) -> tuple[str, list[str]]:
         """构建贴纸叠加滤镜链.
 
         Args:
diff --git a/tests/unit/test_cover_reverse_sticker.py b/tests/unit/test_cover_reverse_sticker.py
index b788d1a60..b2460494b 100755
--- a/tests/unit/test_cover_reverse_sticker.py
+++ b/tests/unit/test_cover_reverse_sticker.py
@@ -11,18 +11,17 @@ from typing import Any
 from unittest.mock import MagicMock, patch
 
 import pytest
-
 from video_processing.cover_generator import (
-    CoverGenerator,
     DEFAULT_COVER_HEIGHT,
     DEFAULT_COVER_WIDTH,
+    CoverGenerator,
     generate_cover_from_plan,
 )
 from video_processing.reverse_engine import ReverseConfig, ReverseEngine
 from video_processing.sticker_engine import (
-    ImageStickerConfig,
     POSITION_PRESETS,
     STICKER_CATEGORIES,
+    ImageStickerConfig,
     StickerEngine,
     TextStickerConfig,
     get_sticker_categories,
@@ -33,13 +32,13 @@ from video_processing.unified_render_service import (
     UnifiedRenderService,
 )
 
-
 # ── Fixtures ──────────────────────────────────────────────────────────────────
 
 
 @dataclass
 class FakePlan:
     """模拟 EditPlan."""
+
     id: str = "plan_001"
     name: str = "测试计划"
     config: dict[str, Any] = field(default_factory=dict)
@@ -90,22 +89,26 @@ class TestReverseConfig:
 
     def test_video_only(self):
         """只倒放视频."""
-        config = ReverseConfig.from_dict({
-            "enabled": True,
-            "reverse_video": True,
-            "reverse_audio": False,
-        })
+        config = ReverseConfig.from_dict(
+            {
+                "enabled": True,
+                "reverse_video": True,
+                "reverse_audio": False,
+            }
+        )
         assert config.enabled is True
         assert config.reverse_video is True
         assert config.reverse_audio is False
 
     def test_audio_only(self):
         """只倒放音频."""
-        config = ReverseConfig.from_dict({
-            "enabled": True,
-            "reverse_video": False,
-            "reverse_audio": True,
-        })
+        config = ReverseConfig.from_dict(
+            {
+                "enabled": True,
+                "reverse_video": False,
+                "reverse_audio": True,
+            }
+        )
         assert config.reverse_video is False
         assert config.reverse_audio is True
 
@@ -253,9 +256,7 @@ class TestTextSticker:
             font_color="#FFFFFF",
             position="center",
         )
-        f = StickerEngine._build_drawtext_filter(
-            sticker, "[in]", "[out]", 1080, 1920
-        )
+        f = StickerEngine._build_drawtext_filter(sticker, "[in]", "[out]", 1080, 1920)
         assert "drawtext" in f
         assert "Hello World" in f
         assert "fontsize=36" in f
@@ -270,9 +271,7 @@ class TestTextSticker:
             stroke_width=3,
             stroke_color="#FF0000",
         )
-        f = StickerEngine._build_drawtext_filter(
-            sticker, "[in]", "[out]", 1080, 1920
-        )
+        f = StickerEngine._build_drawtext_filter(sticker, "[in]", "[out]", 1080, 1920)
         assert "borderw=3" in f
         assert "bordercolor=#FF0000" in f
 
@@ -285,9 +284,7 @@ class TestTextSticker:
             shadow_y=4,
             shadow_alpha=0.5,
         )
-        f = StickerEngine._build_drawtext_filter(
-            sticker, "[in]", "[out]", 1080, 1920
-        )
+        f = StickerEngine._build_drawtext_filter(sticker, "[in]", "[out]", 1080, 1920)
         assert "shadowx=4" in f
         assert "shadowy=4" in f
 
@@ -299,17 +296,13 @@ class TestTextSticker:
             start_time=2.0,
             duration=3.0,
         )
-        f = StickerEngine._build_drawtext_filter(
-            sticker, "[in]", "[out]", 1080, 1920
-        )
+        f = StickerEngine._build_drawtext_filter(sticker, "[in]", "[out]", 1080, 1920)
         assert "enable='between(t,2.0,5.0)'" in f
 
     def test_drawtext_empty_text(self):
         """空文字直通."""
         sticker = TextStickerConfig(enabled=True, text="")
-        f = StickerEngine._build_drawtext_filter(
-            sticker, "[in]", "[out]", 1080, 1920
-        )
+        f = StickerEngine._build_drawtext_filter(sticker, "[in]", "[out]", 1080, 1920)
         assert "[in]copy[out]" in f
 
     def test_drawtext_with_fade(self):
@@ -322,9 +315,7 @@ class TestTextSticker:
             fade_in=0.5,
             fade_out=0.5,
         )
-        f = StickerEngine._build_drawtext_filter(
-            sticker, "[in]", "[out]", 1080, 1920
-        )
+        f = StickerEngine._build_drawtext_filter(sticker, "[in]", "[out]", 1080, 1920)
         assert "alpha=" in f
 
 
@@ -334,14 +325,16 @@ class TestImageSticker:
     def test_image_sticker_overlay(self, sample_image):
         """图片贴纸 overlay 滤镜生成."""
         result = StickerEngine.build_sticker_chain(
-            stickers=[{
-                "type": "image",
-                "image_path": str(sample_image),
-                "position": "top_right",
-                "scale": 0.5,
-                "opacity": 0.8,
-                "z_index": 10,
-            }],
+            stickers=[
+                {
+                    "type": "image",
+                    "image_path": str(sample_image),
+                    "position": "top_right",
+                    "scale": 0.5,
+                    "opacity": 0.8,
+                    "z_index": 10,
+                }
+            ],
             input_label="[base]",
             output_label="[final]",
             canvas_w=1080,
@@ -355,11 +348,13 @@ class TestImageSticker:
     def test_image_sticker_missing_file(self):
         """图片贴纸素材不存在时跳过."""
         result = StickerEngine.build_sticker_chain(
-            stickers=[{
-                "type": "image",
-                "image_path": "/nonexistent/image.png",
-                "position": "center",
-            }],
+            stickers=[
+                {
+                    "type": "image",
+                    "image_path": "/nonexistent/image.png",
+                    "position": "center",
+                }
+            ],
             input_label="[in]",
             output_label="[out]",
             canvas_w=1080,
@@ -486,11 +481,14 @@ class TestCoverGenerator:
             output_path = Path(cmd[-1])
             output_path.parent.mkdir(parents=True, exist_ok=True)
             output_path.write_bytes(b"fake jpeg data")
+
         mock_run.side_effect = fake_run_ffmpeg
 
         output = tmp_path / "cover.jpg"
         result = CoverGenerator.extract_frame(
-            sample_video, output, time_sec=2.0,
+            sample_video,
+            output,
+            time_sec=2.0,
         )
 
         assert result == output
@@ -512,11 +510,14 @@ class TestCoverGenerator:
             output_path = Path(cmd[-1])
             output_path.parent.mkdir(parents=True, exist_ok=True)
             output_path.write_bytes(b"fake jpeg data")
+
         mock_run.side_effect = fake_run_ffmpeg
 
         output = tmp_path / "cover.jpg"
         CoverGenerator.extract_frame(
-            sample_video, output, time_sec=100.0,  # 超过视频时长
+            sample_video,
+            output,
+            time_sec=100.0,  # 超过视频时长
         )
 
         cmd = mock_run.call_args[0][0]
@@ -535,11 +536,14 @@ class TestCoverGenerator:
             output_path = Path(cmd[-1])
             output_path.parent.mkdir(parents=True, exist_ok=True)
             output_path.write_bytes(b"fake jpeg data")
+
         mock_run.side_effect = fake_run_ffmpeg
 
         output = tmp_path / "cover.jpg"
         CoverGenerator.extract_frame(
-            sample_video, output, time_sec=-5.0,
+            sample_video,
+            output,
+            time_sec=-5.0,
         )
 
         cmd = mock_run.call_args[0][0]
@@ -578,7 +582,9 @@ class TestCoverGenerator:
 
         output = tmp_path / "smart_cover.jpg"
         result = CoverGenerator.extract_smart_cover(
-            sample_video, output, frame_count=3,
+            sample_video,
+            output,
+            frame_count=3,
         )
 
         assert result == output
@@ -605,7 +611,8 @@ class TestCoverGenerator:
         output = tmp_path / "custom_cover.jpg"
 
         result = CoverGenerator.process_custom_cover(
-            sample_image, output,
+            sample_image,
+            output,
         )
 
         assert result == output
@@ -628,7 +635,10 @@ class TestCoverGenerator:
         mock_extract.return_value = output
 
         result = CoverGenerator.generate_cover(
-            sample_video, output, mode="time", time_sec=3.0,
+            sample_video,
+            output,
+            mode="time",
+            time_sec=3.0,
         )
 
         assert result == output
@@ -641,7 +651,9 @@ class TestCoverGenerator:
         mock_smart.return_value = output
 
         result = CoverGenerator.generate_cover(
-            sample_video, output, mode="smart",
+            sample_video,
+            output,
+            mode="smart",
         )
 
         assert result == output
@@ -654,7 +666,10 @@ class TestCoverGenerator:
         mock_custom.return_value = output
 
         result = CoverGenerator.generate_cover(
-            sample_video, output, mode="custom", custom_image=sample_image,
+            sample_video,
+            output,
+            mode="custom",
+            custom_image=sample_image,
         )
 
         assert result == output
@@ -692,8 +707,7 @@ class TestGenerateCoverFromPlan:
 # ═══════════════════════════════════════════════════════════════════════════════
 
 
-def _make_clip(clip_id="c1", asset_id="a1", path=Path("/fake/video.mp4"),
-               clip_type="main", config=None):
+def _make_clip(clip_id="c1", asset_id="a1", path=Path("/fake/video.mp4"), clip_type="main", config=None):
     """创建测试用 ResolvedClip."""
     return ResolvedClip(
         clip_id=clip_id,
@@ -712,6 +726,7 @@ def _make_clip(clip_id="c1", asset_id="a1", path=Path("/fake/video.mp4"),
 def _make_service(plan, clips, asset_path_map=None, work_dir=None, tmp_path=None):
     """创建测试用 UnifiedRenderService."""
     from pathlib import Path as P
+
     work_dir = work_dir or (tmp_path or P("/tmp")) / "render_test"
     work_dir.mkdir(exist_ok=True, parents=True)
     return UnifiedRenderService(
@@ -748,6 +763,7 @@ class TestReverseIntegration:
 
         # 直接测 _build_filter_complex
         from video_processing.unified_render_service import RenderLayer
+
         layer = RenderLayer(role="main", clips=[clip, clip2])
         filter_str, inputs = service._build_filter_complex([layer])
 
@@ -761,6 +777,7 @@ class TestReverseIntegration:
 
         service = _make_service(plan, [clip], tmp_path=tmp_path)
         from video_processing.unified_render_service import RenderLayer
+
         layer = RenderLayer(role="main", clips=[clip])
         layers = [layer]
 
@@ -772,14 +789,13 @@ class TestStickerIntegration:
 
     def test_can_use_pass_through_with_stickers(self, tmp_path):
         """有贴纸时禁用直通模式."""
-        plan = FakePlan(id="p1", config={
-            "stickers": [{"type": "text", "text": "Hello", "position": "center"}]
-        })
+        plan = FakePlan(id="p1", config={"stickers": [{"type": "text", "text": "Hello", "position": "center"}]})
         clip = _make_clip()
         clip.actual_duration = 5.0
 
         service = _make_service(plan, [clip], tmp_path=tmp_path)
         from video_processing.unified_render_service import RenderLayer
+
         layer = RenderLayer(role="main", clips=[clip])
         layers = [layer]
 
@@ -793,6 +809,7 @@ class TestStickerIntegration:
 
         service = _make_service(plan, [clip], tmp_path=tmp_path)
         from video_processing.unified_render_service import RenderLayer
+
         layer = RenderLayer(role="main", clips=[clip])
         layers = [layer]
 
@@ -800,11 +817,9 @@ class TestStickerIntegration:
 
     def test_build_sticker_filters_text(self, tmp_path):
         """文字贴纸滤镜构建."""
-        plan = FakePlan(id="p1", config={
-            "stickers": [
-                {"type": "text", "text": "Hello", "position": "top_center", "z_index": 10}
-            ]
-        })
+        plan = FakePlan(
+            id="p1", config={"stickers": [{"type": "text", "text": "Hello", "position": "top_center", "z_index": 10}]}
+        )
         service = _make_service(plan, [], tmp_path=tmp_path)
 
         filter_str, extra_inputs = service._build_sticker_filters("in", "out")
@@ -824,16 +839,19 @@ class TestStickerIntegration:
 
     def test_build_sticker_filters_image(self, sample_image, tmp_path):
         """图片贴纸滤镜构建 + 额外输入."""
-        plan = FakePlan(id="p1", config={
-            "stickers": [
-                {
-                    "type": "image",
-                    "image_path": str(sample_image),
-                    "position": "bottom_right",
-                    "z_index": 5,
-                }
-            ]
-        })
+        plan = FakePlan(
+            id="p1",
+            config={
+                "stickers": [
+                    {
+                        "type": "image",
+                        "image_path": str(sample_image),
+                        "position": "bottom_right",
+                        "z_index": 5,
+                    }
+                ]
+            },
+        )
         service = _make_service(plan, [], tmp_path=tmp_path)
 
         filter_str, extra_inputs = service._build_sticker_filters("in", "out")