Eliminate Python page helpers from account, federation, and cart

All three services now fetch page data via (service ...) IO primitives
in .sx defpages instead of Python middleman functions.

- Account: newsletters-data → AccountPageService.newsletters_data
- Federation: 8 page helpers → FederationPageService methods
  (timeline, compose, search, following, followers, notifications)
- Cart: 4 page helpers → CartPageService methods
  (overview, page-cart, admin, payments)
- Serializers moved to service modules, thin delegates kept for routes
- ~520 lines of Python page helpers removed

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

federation/services/__init__.py

@@ -13,3 +13,6 @@ def register_domain_services() -> None:
     from shared.services.federation_impl import SqlFederationService
 
     services.federation = SqlFederationService()
+
+    from .federation_page import FederationPageService
+    services.register("federation_page", FederationPageService())

federation/services/federation_page.py

@@ -0,0 +1,205 @@
+"""Federation page data service — provides serialized dicts for .sx defpages."""
+from __future__ import annotations
+
+
+def _serialize_actor(actor) -> dict | None:
+    if not actor:
+        return None
+    return {
+        "id": actor.id,
+        "preferred_username": actor.preferred_username,
+        "display_name": getattr(actor, "display_name", None),
+        "icon_url": getattr(actor, "icon_url", None),
+        "summary": getattr(actor, "summary", None),
+        "actor_url": getattr(actor, "actor_url", ""),
+        "domain": getattr(actor, "domain", ""),
+    }
+
+
+def _serialize_timeline_item(item) -> dict:
+    published = getattr(item, "published", None)
+    return {
+        "object_id": getattr(item, "object_id", "") or "",
+        "author_inbox": getattr(item, "author_inbox", "") or "",
+        "actor_icon": getattr(item, "actor_icon", None),
+        "actor_name": getattr(item, "actor_name", "?"),
+        "actor_username": getattr(item, "actor_username", ""),
+        "actor_domain": getattr(item, "actor_domain", ""),
+        "content": getattr(item, "content", ""),
+        "summary": getattr(item, "summary", None),
+        "published": published.strftime("%b %d, %H:%M") if published else "",
+        "before_cursor": published.isoformat() if published else "",
+        "url": getattr(item, "url", None),
+        "post_type": getattr(item, "post_type", ""),
+        "boosted_by": getattr(item, "boosted_by", None),
+        "like_count": getattr(item, "like_count", 0) or 0,
+        "boost_count": getattr(item, "boost_count", 0) or 0,
+        "liked_by_me": getattr(item, "liked_by_me", False),
+        "boosted_by_me": getattr(item, "boosted_by_me", False),
+    }
+
+
+def _serialize_remote_actor(a) -> dict:
+    return {
+        "id": getattr(a, "id", None),
+        "display_name": getattr(a, "display_name", None) or getattr(a, "preferred_username", ""),
+        "preferred_username": getattr(a, "preferred_username", ""),
+        "domain": getattr(a, "domain", ""),
+        "icon_url": getattr(a, "icon_url", None),
+        "actor_url": getattr(a, "actor_url", ""),
+        "summary": getattr(a, "summary", None),
+    }
+
+
+def _get_actor():
+    from quart import g
+    return getattr(g, "_social_actor", None)
+
+
+def _require_actor():
+    from quart import abort
+    actor = _get_actor()
+    if not actor:
+        abort(403, "You need to choose a federation username first")
+    return actor
+
+
+class FederationPageService:
+    """Service for federation page data, callable via (service "federation-page" ...)."""
+
+    async def home_timeline_data(self, session, **kw):
+        actor = _require_actor()
+        from shared.services.registry import services
+        items = await services.federation.get_home_timeline(session, actor.id)
+        return {
+            "items": [_serialize_timeline_item(i) for i in items],
+            "timeline_type": "home",
+            "actor": _serialize_actor(actor),
+        }
+
+    async def public_timeline_data(self, session, **kw):
+        actor = _get_actor()
+        from shared.services.registry import services
+        items = await services.federation.get_public_timeline(session)
+        return {
+            "items": [_serialize_timeline_item(i) for i in items],
+            "timeline_type": "public",
+            "actor": _serialize_actor(actor),
+        }
+
+    async def compose_data(self, session, **kw):
+        from quart import request
+        _require_actor()
+        reply_to = request.args.get("reply_to")
+        return {"reply_to": reply_to or None}
+
+    async def search_data(self, session, **kw):
+        from quart import request
+        actor = _get_actor()
+        from shared.services.registry import services
+        query = request.args.get("q", "").strip()
+        actors_list = []
+        total = 0
+        followed_urls: list[str] = []
+        if query:
+            actors_list, total = await services.federation.search_actors(session, query)
+            if actor:
+                following, _ = await services.federation.get_following(
+                    session, actor.preferred_username, page=1, per_page=1000,
+                )
+                followed_urls = [a.actor_url for a in following]
+        return {
+            "query": query,
+            "actors": [_serialize_remote_actor(a) for a in actors_list],
+            "total": total,
+            "followed_urls": followed_urls,
+            "actor": _serialize_actor(actor),
+        }
+
+    async def following_data(self, session, **kw):
+        actor = _require_actor()
+        from shared.services.registry import services
+        actors_list, total = await services.federation.get_following(
+            session, actor.preferred_username,
+        )
+        return {
+            "actors": [_serialize_remote_actor(a) for a in actors_list],
+            "total": total,
+            "actor": _serialize_actor(actor),
+        }
+
+    async def followers_data(self, session, **kw):
+        actor = _require_actor()
+        from shared.services.registry import services
+        actors_list, total = await services.federation.get_followers_paginated(
+            session, actor.preferred_username,
+        )
+        following, _ = await services.federation.get_following(
+            session, actor.preferred_username, page=1, per_page=1000,
+        )
+        followed_urls = [a.actor_url for a in following]
+        return {
+            "actors": [_serialize_remote_actor(a) for a in actors_list],
+            "total": total,
+            "followed_urls": followed_urls,
+            "actor": _serialize_actor(actor),
+        }
+
+    async def actor_timeline_data(self, session, *, id=None, **kw):
+        from quart import abort
+        from sqlalchemy import select as sa_select
+        from shared.models.federation import RemoteActor
+        from shared.services.registry import services
+        from shared.services.federation_impl import _remote_actor_to_dto
+
+        actor = _get_actor()
+        actor_id = id
+        remote = (
+            await session.execute(
+                sa_select(RemoteActor).where(RemoteActor.id == actor_id)
+            )
+        ).scalar_one_or_none()
+        if not remote:
+            abort(404)
+        remote_dto = _remote_actor_to_dto(remote)
+        items = await services.federation.get_actor_timeline(session, actor_id)
+        is_following = False
+        if actor:
+            from shared.models.federation import APFollowing
+            existing = (
+                await session.execute(
+                    sa_select(APFollowing).where(
+                        APFollowing.actor_profile_id == actor.id,
+                        APFollowing.remote_actor_id == actor_id,
+                    )
+                )
+            ).scalar_one_or_none()
+            is_following = existing is not None
+        return {
+            "remote_actor": _serialize_remote_actor(remote_dto),
+            "items": [_serialize_timeline_item(i) for i in items],
+            "is_following": is_following,
+            "actor": _serialize_actor(actor),
+        }
+
+    async def notifications_data(self, session, **kw):
+        actor = _require_actor()
+        from shared.services.registry import services
+        items = await services.federation.get_notifications(session, actor.id)
+        await services.federation.mark_notifications_read(session, actor.id)
+
+        notif_dicts = []
+        for n in items:
+            created = getattr(n, "created_at", None)
+            notif_dicts.append({
+                "from_actor_name": getattr(n, "from_actor_name", "?"),
+                "from_actor_username": getattr(n, "from_actor_username", ""),
+                "from_actor_domain": getattr(n, "from_actor_domain", ""),
+                "from_actor_icon": getattr(n, "from_actor_icon", None),
+                "notification_type": getattr(n, "notification_type", ""),
+                "target_content_preview": getattr(n, "target_content_preview", None),
+                "created_at_formatted": created.strftime("%b %d, %H:%M") if created else "",
+                "read": getattr(n, "read", True),
+                "app_domain": getattr(n, "app_domain", ""),
+            })
+        return {"notifications": notif_dicts}