Hoàn thành bước 3.3. Interactive Workbook (The Core Viewer)

backend/app/schemas.py

@@ -63,3 +63,19 @@ class PDFUploadResult(BaseModel):
     success: bool
     pdf: PDFOut | None = None
     error: str | None = None
+
+
+# ── Annotations ───────────────────────────────────────────────────────────────
+
+class AnnotationIn(BaseModel):
+    canvas_data: dict
+
+
+class AnnotationOut(BaseModel):
+    id: int
+    pdf_id: int
+    page_number: int
+    canvas_data: dict
+    updated_at: datetime
+
+    model_config = {"from_attributes": True}