feat(attachments): PostAttachment model + 0009 (table + batch counter)

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

backend/app/models/__init__.py

@@ -11,6 +11,7 @@ from .import_settings import ImportSettings
 from .import_task import ImportTask
 from .ml_settings import MLSettings
 from .post import Post
+from .post_attachment import PostAttachment
 from .series_page import SeriesPage
 from .source import Source
 from .tag import Tag, TagKind, image_tag
@@ -25,6 +26,7 @@ __all__ = [
     "Source",
     "Credential",
     "Post",
+    "PostAttachment",
     "SeriesPage",
     "ImageRecord",
     "ImageProvenance",

backend/app/models/import_batch.py

@@ -25,6 +25,7 @@ class ImportBatch(Base):
     imported: Mapped[int] = mapped_column(Integer, nullable=False, default=0)
     skipped: Mapped[int] = mapped_column(Integer, nullable=False, default=0)
     failed: Mapped[int] = mapped_column(Integer, nullable=False, default=0)
+    attachments: Mapped[int] = mapped_column(Integer, nullable=False, default=0)
 
     status: Mapped[str] = mapped_column(String(16), nullable=False, default="running", index=True)
     # running | complete | cancelled

backend/app/models/post_attachment.py

@@ -0,0 +1,47 @@
+"""PostAttachment — a non-art file preserved from a post.
+
+Art images become ImageRecords; everything else a post contained
+(archives, .exe, .pdf, ...) is captured here so nothing is lost.
+post_id is nullable (set only when an adjacent sidecar yields a Post);
+artist_id mirrors the canonical attribution model (FC-2d-vii-c). Both
+FKs are SET NULL so deleting a Post/Artist never deletes the preserved
+binary row.
+"""
+
+from datetime import datetime
+
+from sqlalchemy import (
+    BigInteger,
+    DateTime,
+    ForeignKey,
+    Integer,
+    String,
+    Text,
+    func,
+)
+from sqlalchemy.orm import Mapped, mapped_column
+
+from .base import Base
+
+
+class PostAttachment(Base):
+    __tablename__ = "post_attachment"
+
+    id: Mapped[int] = mapped_column(Integer, primary_key=True)
+    post_id: Mapped[int | None] = mapped_column(
+        ForeignKey("post.id", ondelete="SET NULL"), nullable=True, index=True
+    )
+    artist_id: Mapped[int | None] = mapped_column(
+        ForeignKey("artist.id", ondelete="SET NULL"), nullable=True, index=True
+    )
+    sha256: Mapped[str] = mapped_column(
+        String(64), nullable=False, unique=True, index=True
+    )
+    path: Mapped[str] = mapped_column(Text, nullable=False)
+    original_filename: Mapped[str] = mapped_column(Text, nullable=False)
+    ext: Mapped[str] = mapped_column(String(32), nullable=False)
+    mime: Mapped[str | None] = mapped_column(String(128), nullable=True)
+    size_bytes: Mapped[int] = mapped_column(BigInteger, nullable=False)
+    captured_at: Mapped[datetime] = mapped_column(
+        DateTime(timezone=True), nullable=False, server_default=func.now()
+    )