Rescue Paperjet v1 implementation

backend/app/models/__init__.py

@@ -5,9 +5,9 @@ All models use UUIDv4 string primary keys (except the singleton settings row).
 Timestamps are stored as ISO8601 TEXT columns.
 """
 
-from app.models.settings import Settings
-from app.models.document import Document
 from app.models.annotation_state import AnnotationState
+from app.models.document import Document
+from app.models.settings import Settings
 from app.models.version import Version
 
-__all__ = ["Settings", "Document", "AnnotationState", "Version"]
+__all__ = ["AnnotationState", "Document", "Settings", "Version"]

backend/app/models/annotation_state.py

@@ -1,15 +1,19 @@
 """AnnotationState model — current working annotation layer per document."""
 
-from datetime import datetime, timezone
+from datetime import UTC, datetime
+from typing import TYPE_CHECKING
 
 from sqlalchemy import ForeignKey, Text
 from sqlalchemy.orm import Mapped, mapped_column, relationship
 
 from app.db import Base
 
+if TYPE_CHECKING:
+    from app.models.document import Document
+
 
 def _now_iso() -> str:
-    return datetime.now(timezone.utc).isoformat()
+    return datetime.now(UTC).isoformat()
 
 
 class AnnotationState(Base):

backend/app/models/document.py

@@ -1,20 +1,25 @@
 """Document model — uploaded PDFs with soft-delete support."""
 
 import uuid
-from datetime import datetime, timezone
+from datetime import UTC, datetime
+from typing import TYPE_CHECKING
 
 from sqlalchemy import Index, Integer, Text
 from sqlalchemy.orm import Mapped, mapped_column, relationship
 
 from app.db import Base
 
+if TYPE_CHECKING:
+    from app.models.annotation_state import AnnotationState
+    from app.models.version import Version
+
 
 def _uuid() -> str:
     return str(uuid.uuid4())
 
 
 def _now_iso() -> str:
-    return datetime.now(timezone.utc).isoformat()
+    return datetime.now(UTC).isoformat()
 
 
 class Document(Base):

backend/app/models/settings.py

@@ -1,6 +1,6 @@
 """Settings model — singleton row for app-wide configuration."""
 
-from datetime import datetime, timezone
+from datetime import UTC, datetime
 
 from sqlalchemy import Integer, Text
 from sqlalchemy.orm import Mapped, mapped_column
@@ -22,10 +22,10 @@ class Settings(Base):
     password_hash: Mapped[str | None] = mapped_column(Text, nullable=True, default=None)
     created_at: Mapped[str] = mapped_column(
         Text,
-        default=lambda: datetime.now(timezone.utc).isoformat(),
+        default=lambda: datetime.now(UTC).isoformat(),
     )
     updated_at: Mapped[str] = mapped_column(
         Text,
-        default=lambda: datetime.now(timezone.utc).isoformat(),
-        onupdate=lambda: datetime.now(timezone.utc).isoformat(),
+        default=lambda: datetime.now(UTC).isoformat(),
+        onupdate=lambda: datetime.now(UTC).isoformat(),
     )

backend/app/models/version.py

@@ -1,20 +1,24 @@
 """Version model — annotation state snapshots for history/recovery."""
 
 import uuid
-from datetime import datetime, timezone
+from datetime import UTC, datetime
+from typing import TYPE_CHECKING
 
 from sqlalchemy import ForeignKey, Index, Text
 from sqlalchemy.orm import Mapped, mapped_column, relationship
 
 from app.db import Base
 
+if TYPE_CHECKING:
+    from app.models.document import Document
+
 
 def _uuid() -> str:
     return str(uuid.uuid4())
 
 
 def _now_iso() -> str:
-    return datetime.now(timezone.utc).isoformat()
+    return datetime.now(UTC).isoformat()
 
 
 class Version(Base):
@@ -40,6 +44,4 @@ class Version(Base):
     # Relationships
     document: Mapped["Document"] = relationship("Document", back_populates="versions")
 
-    __table_args__ = (
-        Index("ix_versions_document_created", "document_id", "created_at"),
-    )
+    __table_args__ = (Index("ix_versions_document_created", "document_id", "created_at"),)