Рабочий пайплайн: YouTube -> транскрипция -> выжимка -> Postgres

- новый api/: /pipeline/process (yt-dlp, субтитры или Vosk, LLM/экстрактивная
  суммаризация), /videos, /llm; старый код перенесён в api_legacy/
- web/: Flet UI (flet 0.28.3 + flet-web, порт 8550)
- Dockerfile.api: ffmpeg слоем из mwader/static-ffmpeg, pip с кэш-маунтом
- requirements/pyproject: убраны moviepy, imageio-ffmpeg, битый asyncio
- README с инструкцией запуска и загрузкой Vosk-модели

Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>

api/db/video.py

@@ -0,0 +1,53 @@
+from sqlalchemy import select
+
+from api.db.connection import SessionLocal
+from api.models.video import Video
+
+
+async def create_video(
+    *,
+    uuid: str,
+    source_url: str,
+    title: str,
+    video_path: str,
+    text_full_path: str,
+    text_summary_path: str,
+    transcription_method: str,
+) -> Video:
+    async with SessionLocal() as session:
+        v = Video(
+            uuid=uuid,
+            source_url=source_url,
+            title=title or "",
+            video_path=video_path or "",
+            text_full_path=text_full_path or "",
+            text_summary_path=text_summary_path or "",
+            transcription_method=transcription_method or "",
+        )
+        session.add(v)
+        await session.commit()
+        await session.refresh(v)
+        return v
+
+
+async def get_video(video_uuid: str) -> Video | None:
+    async with SessionLocal() as session:
+        res = await session.execute(select(Video).where(Video.uuid == video_uuid))
+        return res.scalars().first()
+
+
+async def list_videos() -> list[Video]:
+    async with SessionLocal() as session:
+        res = await session.execute(select(Video).order_by(Video.created_at.desc()))
+        return list(res.scalars().all())
+
+
+async def delete_video(video_uuid: str) -> bool:
+    async with SessionLocal() as session:
+        res = await session.execute(select(Video).where(Video.uuid == video_uuid))
+        v = res.scalars().first()
+        if not v:
+            return False
+        await session.delete(v)
+        await session.commit()
+        return True