Track status changes for unpublish + edit federation events

- _upsert_post returns (post, old_status) to detect status transitions
- Emit post.unpublished when published→draft (triggers Delete activity)
- Emit post.updated only when already-published posts are edited
- Emit post.published only for new publishes (not re-syncs)
- Same logic for pages via sync_single_page

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

bp/blog/ghost/ghost_sync.py

@@ -209,12 +209,15 @@ def _apply_ghost_fields(obj: Post, gp: Dict[str, Any], author_map: Dict[str, Aut
     obj.primary_tag_id = tag_map[pt["id"].strip()].id if (pt and pt["id"] in tag_map) else None  # type: ignore[index]
 
 
-async def _upsert_post(sess: AsyncSession, gp: Dict[str, Any], author_map: Dict[str, Author], tag_map: Dict[str, Tag]) -> Post:
+async def _upsert_post(sess: AsyncSession, gp: Dict[str, Any], author_map: Dict[str, Author], tag_map: Dict[str, Tag]) -> tuple[Post, str | None]:
+    """Upsert a post. Returns (post, old_status) where old_status is None for new rows."""
     from sqlalchemy.exc import IntegrityError
 
     res = await sess.execute(select(Post).where(Post.ghost_id == gp["id"]))
     obj = res.scalar_one_or_none()
 
+    old_status = obj.status if obj is not None else None
+
     if obj is not None:
         # Row exists — just update
         _apply_ghost_fields(obj, gp, author_map, tag_map)
@@ -1018,25 +1021,40 @@ async def sync_single_post(sess: AsyncSession, ghost_id: str) -> None:
         tag_obj = await _upsert_tag(sess, pt)
         tag_map[pt["id"]] = tag_obj
 
-    post = await _upsert_post(sess, gp, author_map, tag_map)
+    post, old_status = await _upsert_post(sess, gp, author_map, tag_map)
 
-    # Emit federation event for published posts (not pages, not drafts)
-    if post.status == "published" and not post.is_page and post.user_id:
+    # Emit federation events for posts (not pages)
+    if not post.is_page and post.user_id:
         from shared.events import emit_event
         from shared.infrastructure.urls import app_url
-        event_type = "post.published" if post.created_at == post.updated_at else "post.updated"
-        await emit_event(
-            sess,
-            event_type=event_type,
-            aggregate_type="Post",
-            aggregate_id=post.id,
-            payload={
-                "user_id": post.user_id,
-                "title": post.title or "",
-                "excerpt": post.custom_excerpt or post.excerpt or "",
-                "url": app_url("coop", f"/{post.slug}/"),
-            },
-        )
+        post_url = app_url("coop", f"/{post.slug}/")
+
+        if post.status == "published":
+            event_type = "post.published" if old_status != "published" else "post.updated"
+            await emit_event(
+                sess,
+                event_type=event_type,
+                aggregate_type="Post",
+                aggregate_id=post.id,
+                payload={
+                    "user_id": post.user_id,
+                    "title": post.title or "",
+                    "excerpt": post.custom_excerpt or post.excerpt or "",
+                    "url": post_url,
+                },
+            )
+        elif old_status == "published" and post.status != "published":
+            # Unpublished — notify federation to send Delete
+            await emit_event(
+                sess,
+                event_type="post.unpublished",
+                aggregate_type="Post",
+                aggregate_id=post.id,
+                payload={
+                    "user_id": post.user_id,
+                    "url": post_url,
+                },
+            )
 
 
 async def sync_single_page(sess: AsyncSession, ghost_id: str) -> None:
@@ -1069,25 +1087,39 @@ async def sync_single_page(sess: AsyncSession, ghost_id: str) -> None:
         tag_obj = await _upsert_tag(sess, pt)
         tag_map[pt["id"]] = tag_obj
 
-    post = await _upsert_post(sess, gp, author_map, tag_map)
+    post, old_status = await _upsert_post(sess, gp, author_map, tag_map)
 
-    # Emit federation event for published pages
-    if post.status == "published" and post.user_id:
+    # Emit federation events for pages
+    if post.user_id:
         from shared.events import emit_event
         from shared.infrastructure.urls import app_url
-        event_type = "post.published" if post.created_at == post.updated_at else "post.updated"
-        await emit_event(
-            sess,
-            event_type=event_type,
-            aggregate_type="Post",
-            aggregate_id=post.id,
-            payload={
-                "user_id": post.user_id,
-                "title": post.title or "",
-                "excerpt": post.custom_excerpt or post.excerpt or "",
-                "url": app_url("coop", f"/{post.slug}/"),
-            },
-        )
+        post_url = app_url("coop", f"/{post.slug}/")
+
+        if post.status == "published":
+            event_type = "post.published" if old_status != "published" else "post.updated"
+            await emit_event(
+                sess,
+                event_type=event_type,
+                aggregate_type="Post",
+                aggregate_id=post.id,
+                payload={
+                    "user_id": post.user_id,
+                    "title": post.title or "",
+                    "excerpt": post.custom_excerpt or post.excerpt or "",
+                    "url": post_url,
+                },
+            )
+        elif old_status == "published" and post.status != "published":
+            await emit_event(
+                sess,
+                event_type="post.unpublished",
+                aggregate_type="Post",
+                aggregate_id=post.id,
+                payload={
+                    "user_id": post.user_id,
+                    "url": post_url,
+                },
+            )
 
 
 async def sync_single_author(sess: AsyncSession, ghost_id: str) -> None: