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/connection.py

@@ -1,27 +1,63 @@
-from sqlalchemy.ext.asyncio import create_async_engine, AsyncSession
-from sqlalchemy.orm import sessionmaker
-from sqlalchemy import text
 import asyncio
-from api.config import settings
+import logging
 
-DATABASE_URL = settings.DATABASE_URL
-engine = create_async_engine(DATABASE_URL, echo=False, future=True)
+import asyncpg
+from sqlalchemy import text
+from sqlalchemy.ext.asyncio import AsyncSession, create_async_engine
+from sqlalchemy.orm import sessionmaker
+
+from api.config import settings
+from api.models.base import Base
+import api.models.video  # noqa: F401  - register model with Base.metadata
+
+
+logger = logging.getLogger("db")
+
+engine = create_async_engine(settings.database_url, echo=False, future=True)
 SessionLocal = sessionmaker(engine, expire_on_commit=False, class_=AsyncSession)
 
 
-async def wait_for_db(retries: int = 30, delay: float = 1.0) -> None:
-	"""Wait until the database is available. Retries with exponential backoff.
+async def wait_for_postgres(retries: int = 30, delay: float = 1.0) -> None:
+    """Wait for the postgres server to accept connections (using the default 'postgres' db)."""
+    last_exc: Exception | None = None
+    for attempt in range(1, retries + 1):
+        try:
+            conn = await asyncpg.connect(
+                user=settings.DB_USER,
+                password=settings.DB_PASS,
+                database="postgres",
+                host=settings.DB_HOST,
+                port=int(settings.DB_PORT),
+            )
+            await conn.close()
+            return
+        except Exception as e:
+            last_exc = e
+            wait = min(delay * (2 ** (attempt - 1)), 5)
+            logger.info("Waiting for postgres (attempt %s/%s): %s", attempt, retries, e)
+            await asyncio.sleep(wait)
+    raise RuntimeError(f"Could not connect to postgres after {retries} attempts") from last_exc
 
-	Raises RuntimeError if DB is still unavailable after retries.
-	"""
-	last_exc = None
-	for attempt in range(1, retries + 1):
-		try:
-			async with engine.connect() as conn:
-				await conn.execute(text("SELECT 1"))
-				return
-		except Exception as e:
-			last_exc = e
-			wait = min(delay * (2 ** (attempt - 1)), 5)
-			await asyncio.sleep(wait)
-	raise RuntimeError(f"Could not connect to DB after {retries} attempts") from last_exc
+
+async def _create_database_if_missing() -> None:
+    admin = await asyncpg.connect(
+        user=settings.DB_USER,
+        password=settings.DB_PASS,
+        database="postgres",
+        host=settings.DB_HOST,
+        port=int(settings.DB_PORT),
+    )
+    try:
+        exists = await admin.fetchval(
+            "SELECT 1 FROM pg_database WHERE datname=$1", settings.DB_NAME
+        )
+        if not exists:
+            await admin.execute(f'CREATE DATABASE "{settings.DB_NAME}"')
+    finally:
+        await admin.close()
+
+
+async def init_db() -> None:
+    await _create_database_if_missing()
+    async with engine.begin() as conn:
+        await conn.run_sync(Base.metadata.create_all)