feat: import F95 screenshot galleries with AVIF support

backend/app/models.py

@@ -58,6 +58,7 @@ class Game(Base):
     tags: Mapped[list[str]] = mapped_column(ARRAY(String), default=list)
     engine: Mapped[str] = mapped_column(String(32), default="renpy")
     cover_hash: Mapped[str | None] = mapped_column(String(80))
+    gallery_hashes: Mapped[list[str]] = mapped_column(ARRAY(String(80)), default=list, server_default="{}")
     # the version "Play" opens; translations are published by merging into it
     main_version_id: Mapped[int | None] = mapped_column(
         ForeignKey("game_versions.id", ondelete="SET NULL", use_alter=True))