fix: resolve 15 bugs and gaps in video scraper pipeline

- Fix extract_visual_data returning 2-tuple instead of 3 (ValueError crash)
- Move pytesseract from core deps to [video-full] optional group
- Add 30-min timeout + user feedback to video enhancement subprocess
- Add scrape_video_impl to MCP server fallback import block
- Detect auto-generated YouTube captions via is_generated property
- Forward --vision-ocr and --video-playlist through create command
- Fix filename collision for non-ASCII video titles (fallback to video_id)
- Make _vision_used a proper dataclass field on FrameSubSection
- Expose 6 visual params in MCP scrape_video tool
- Add install instructions on missing video deps in unified scraper
- Update MCP docstring tool counts (25→33, 7 categories)
- Add video and word commands to main.py docstring
- Document video-full exclusion from [all] deps in pyproject.toml
- Update parser registry test count (22→23 for video parser)

All 2437 tests passing, 0 failures.

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

src/skill_seekers/cli/video_visual.py

@@ -1864,7 +1864,7 @@ def _ocr_single_panel(
         panel_id=f"panel_{row}_{col}",
     )
     # Stash vision_used flag for the caller to count
-    ss._vision_used = vision_used  # type: ignore[attr-defined]
+    ss._vision_used = vision_used
     return ss
 
 
@@ -1918,7 +1918,7 @@ def extract_visual_data(
     cap = cv2.VideoCapture(video_path)
     if not cap.isOpened():
         logger.error(f"Cannot open video: {video_path}")
-        return [], []
+        return [], [], None
 
     fps = cap.get(cv2.CAP_PROP_FPS) or 30.0
     total_frames = cap.get(cv2.CAP_PROP_FRAME_COUNT)
@@ -2003,7 +2003,7 @@ def extract_visual_data(
                     for fut in concurrent.futures.as_completed(futures):
                         ss = fut.result()
                         if ss is not None:
-                            if getattr(ss, "_vision_used", False):
+                            if ss._vision_used:
                                 vision_api_frames += 1
                             sub_sections.append(ss)
             else:
@@ -2018,7 +2018,7 @@ def extract_visual_data(
                     use_vision_api,
                 )
                 if ss is not None:
-                    if getattr(ss, "_vision_used", False):
+                    if ss._vision_used:
                         vision_api_frames += 1
                     sub_sections.append(ss)