feat: 타임라인 에디터 및 비디오 스튜디오 컴포넌트 추가

- TimelineEditor, VideoStudio 컴포넌트 신규 추가
- 백엔드 transcriber, video_processor 서비스 개선
- 프론트엔드 HomePage 리팩토링 및 스타일 업데이트

🤖 Generated with [Claude Code](https://claude.com/claude-code)

Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>

backend/app/routers/process.py

@@ -116,12 +116,14 @@ async def process_task(
             outline_color=style.outline_color.lstrip("#"),
             font_name=style.font_name,
             position=style.position,  # top, center, bottom
+            margin_v=style.margin_v,
             outline_width=style.outline_width,
             bold=style.bold,
             shadow=style.shadow,
             background_box=style.background_box,
             background_opacity=style.background_opacity,
             animation=style.animation,
+            max_chars_per_line=style.max_chars_per_line,
         )
 
         # Save subtitle file
@@ -284,12 +286,14 @@ async def continue_processing_task(
                 outline_color=style.outline_color.lstrip("#"),
                 font_name=style.font_name,
                 position=style.position,
+                margin_v=style.margin_v,
                 outline_width=style.outline_width,
                 bold=style.bold,
                 shadow=style.shadow,
                 background_box=style.background_box,
                 background_opacity=style.background_opacity,
                 animation=style.animation,
+                max_chars_per_line=style.max_chars_per_line,
             )
 
             job_dir = os.path.dirname(job.video_path)
@@ -511,12 +515,21 @@ async def trim_job_video(
     video_ext = os.path.splitext(job.video_path)[1]
     trimmed_path = os.path.join(video_dir, f"trimmed{video_ext}")
 
+    # Convert exclude_regions to list of dicts for the function
+    exclude_regions = None
+    if request.exclude_regions:
+        exclude_regions = [
+            {'start': region.start, 'end': region.end}
+            for region in request.exclude_regions
+        ]
+
     # Perform trim
     success, message = await trim_video(
         job.video_path,
         trimmed_path,
         request.start_time,
         request.end_time,
+        exclude_regions,
     )
 
     if not success:
@@ -690,6 +703,7 @@ async def render_step_task(
     intro_text: str | None = None,
     intro_duration: float = 0.7,
     intro_font_size: int = 100,
+    intro_position: str = "center",
 ):
     """Background task for final video rendering (subtitle composition + BGM + intro text)."""
     job = job_store.get_job(job_id)
@@ -715,6 +729,7 @@ async def render_step_task(
                 outline_color=style.outline_color.lstrip("#"),
                 font_name=style.font_name,
                 position=style.position,
+                margin_v=style.margin_v,
                 outline_width=style.outline_width,
                 bold=style.bold,
                 shadow=style.shadow,
@@ -722,6 +737,7 @@ async def render_step_task(
                 background_opacity=style.background_opacity,
                 animation=style.animation,
                 time_offset=subtitle_offset,
+                max_chars_per_line=style.max_chars_per_line,
             )
 
             job_dir = os.path.dirname(job.video_path)
@@ -756,6 +772,7 @@ async def render_step_task(
             intro_text=intro_text,
             intro_duration=intro_duration,
             intro_font_size=intro_font_size,
+            intro_position=intro_position,
         )
 
         if success:
@@ -846,6 +863,7 @@ async def render_video(
         request.intro_text,
         request.intro_duration,
         request.intro_font_size,
+        request.intro_position,
     )
 
     return ProcessResponse(