Replace inter-service _handlers dicts with declarative sx defquery/defaction

The inter-service data layer (fetch_data/call_action) was the least
structured part of the codebase — Python _handlers dicts with ad-hoc
param extraction scattered across 16 route files. This replaces them
with declarative .sx query/action definitions that make the entire
inter-service protocol self-describing and greppable.

Infrastructure:
- defquery/defaction special forms in the sx evaluator
- Query/action registry with load, lookup, and schema introspection
- Query executor using async_eval with I/O primitives
- Blueprint factories (create_data_blueprint/create_action_blueprint)
  with sx-first dispatch and Python fallback
- /internal/schema endpoint on every service
- parse-datetime and split-ids primitives for type coercion

Service extractions:
- LikesService (toggle, is_liked, liked_slugs, liked_ids)
- PageConfigService (ensure, get_by_container, get_by_id, get_batch, update)
- RelationsService (wraps module-level functions)
- AccountDataService (user_by_email, newsletters)
- CartItemsService, MarketDataService (raw SQLAlchemy lookups)

50 of 54 handlers converted to sx, 4 Python fallbacks remain
(ghost-sync/push-member, clear-cart-for-order, create-order).
Net: -1,383 lines Python, +251 lines modified.

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

relations/actions.sx

@@ -0,0 +1,36 @@
+;; Relations service — inter-service action endpoints
+
+(defaction attach-child (&key parent-type parent-id child-type child-id
+                          label sort-order relation-type metadata)
+  "Create or revive a container relation."
+  (service "relations" "attach-child"
+    :parent-type parent-type :parent-id parent-id
+    :child-type child-type :child-id child-id
+    :label label :sort-order sort-order
+    :relation-type relation-type :metadata metadata))
+
+(defaction detach-child (&key parent-type parent-id child-type child-id relation-type)
+  "Soft-delete a container relation."
+  (let ((deleted (service "relations" "detach-child"
+                   :parent-type parent-type :parent-id parent-id
+                   :child-type child-type :child-id child-id
+                   :relation-type relation-type)))
+    {"deleted" deleted}))
+
+(defaction relate (&key relation-type from-id to-id label sort-order metadata)
+  "Create a typed relation with registry validation and cardinality enforcement."
+  (service "relations" "relate"
+    :relation-type relation-type :from-id from-id :to-id to-id
+    :label label :sort-order sort-order :metadata metadata))
+
+(defaction unrelate (&key relation-type from-id to-id)
+  "Remove a typed relation with registry validation."
+  (let ((deleted (service "relations" "unrelate"
+                   :relation-type relation-type
+                   :from-id from-id :to-id to-id)))
+    {"deleted" deleted}))
+
+(defaction can-relate (&key relation-type from-id)
+  "Check if a relation can be created (cardinality, registry validation)."
+  (service "relations" "can-relate"
+    :relation-type relation-type :from-id from-id))

relations/bp/actions/routes.py

@@ -1,194 +1,14 @@
-"""Relations app action endpoints."""
+"""Relations app action endpoints.
+
+All actions are defined in ``relations/actions.sx``.
+"""
 from __future__ import annotations
 
-from quart import Blueprint, g, jsonify, request
+from quart import Blueprint
 
-from shared.infrastructure.actions import ACTION_HEADER
+from shared.infrastructure.query_blueprint import create_action_blueprint
 
 
 def register() -> Blueprint:
-    bp = Blueprint("actions", __name__, url_prefix="/internal/actions")
-
-    @bp.before_request
-    async def _require_action_header():
-        if not request.headers.get(ACTION_HEADER):
-            return jsonify({"error": "forbidden"}), 403
-        from shared.infrastructure.internal_auth import validate_internal_request
-        if not validate_internal_request():
-            return jsonify({"error": "forbidden"}), 403
-
-    _handlers: dict[str, object] = {}
-
-    @bp.post("/<action_name>")
-    async def handle_action(action_name: str):
-        handler = _handlers.get(action_name)
-        if handler is None:
-            return jsonify({"error": "unknown action"}), 404
-        try:
-            result = await handler()
-            return jsonify(result)
-        except Exception as exc:
-            import logging
-            logging.getLogger(__name__).exception("Action %s failed", action_name)
-            return jsonify({"error": str(exc)}), 500
-
-    # --- attach-child ---
-    async def _attach_child():
-        """Create or revive a ContainerRelation."""
-        from shared.services.relationships import attach_child
-
-        data = await request.get_json(force=True)
-        rel  = await attach_child(
-            g.s,
-            parent_type=data["parent_type"],
-            parent_id=data["parent_id"],
-            child_type=data["child_type"],
-            child_id=data["child_id"],
-            label=data.get("label"),
-            sort_order=data.get("sort_order"),
-            relation_type=data.get("relation_type"),
-            metadata=data.get("metadata"),
-        )
-        return {
-            "id":          rel.id,
-            "parent_type": rel.parent_type,
-            "parent_id":   rel.parent_id,
-            "child_type":  rel.child_type,
-            "child_id":    rel.child_id,
-            "sort_order":  rel.sort_order,
-            "relation_type": rel.relation_type,
-        }
-
-    _handlers["attach-child"] = _attach_child
-
-    # --- detach-child ---
-    async def _detach_child():
-        """Soft-delete a ContainerRelation."""
-        from shared.services.relationships import detach_child
-
-        data    = await request.get_json(force=True)
-        deleted = await detach_child(
-            g.s,
-            parent_type=data["parent_type"],
-            parent_id=data["parent_id"],
-            child_type=data["child_type"],
-            child_id=data["child_id"],
-            relation_type=data.get("relation_type"),
-        )
-        return {"deleted": deleted}
-
-    _handlers["detach-child"] = _detach_child
-
-    # --- relate (registry-aware) ---
-    async def _relate():
-        """Create a typed relation with registry validation and cardinality enforcement."""
-        from shared.services.relationships import attach_child, get_children
-        from shared.sx.relations import get_relation
-
-        data = await request.get_json(force=True)
-        rel_type = data.get("relation_type")
-        if not rel_type:
-            return {"error": "relation_type is required"}, 400
-
-        defn = get_relation(rel_type)
-        if defn is None:
-            return {"error": f"unknown relation_type: {rel_type}"}, 400
-
-        from_id = data["from_id"]
-        to_id = data["to_id"]
-
-        # Cardinality enforcement
-        if defn.cardinality == "one-to-one":
-            existing = await get_children(
-                g.s,
-                parent_type=defn.from_type,
-                parent_id=from_id,
-                child_type=defn.to_type,
-                relation_type=rel_type,
-            )
-            if existing:
-                return {"error": "one-to-one relation already exists", "existing_id": existing[0].child_id}, 409
-
-        rel = await attach_child(
-            g.s,
-            parent_type=defn.from_type,
-            parent_id=from_id,
-            child_type=defn.to_type,
-            child_id=to_id,
-            label=data.get("label"),
-            sort_order=data.get("sort_order"),
-            relation_type=rel_type,
-            metadata=data.get("metadata"),
-        )
-        return {
-            "id": rel.id,
-            "relation_type": rel.relation_type,
-            "parent_type": rel.parent_type,
-            "parent_id": rel.parent_id,
-            "child_type": rel.child_type,
-            "child_id": rel.child_id,
-            "sort_order": rel.sort_order,
-        }
-
-    _handlers["relate"] = _relate
-
-    # --- unrelate (registry-aware) ---
-    async def _unrelate():
-        """Remove a typed relation with registry validation."""
-        from shared.services.relationships import detach_child
-        from shared.sx.relations import get_relation
-
-        data = await request.get_json(force=True)
-        rel_type = data.get("relation_type")
-        if not rel_type:
-            return {"error": "relation_type is required"}, 400
-
-        defn = get_relation(rel_type)
-        if defn is None:
-            return {"error": f"unknown relation_type: {rel_type}"}, 400
-
-        deleted = await detach_child(
-            g.s,
-            parent_type=defn.from_type,
-            parent_id=data["from_id"],
-            child_type=defn.to_type,
-            child_id=data["to_id"],
-            relation_type=rel_type,
-        )
-        return {"deleted": deleted}
-
-    _handlers["unrelate"] = _unrelate
-
-    # --- can-relate (pre-flight check) ---
-    async def _can_relate():
-        """Check if a relation can be created (cardinality, registry validation)."""
-        from shared.services.relationships import get_children
-        from shared.sx.relations import get_relation
-
-        data = await request.get_json(force=True)
-        rel_type = data.get("relation_type")
-        if not rel_type:
-            return {"error": "relation_type is required"}, 400
-
-        defn = get_relation(rel_type)
-        if defn is None:
-            return {"allowed": False, "reason": f"unknown relation_type: {rel_type}"}
-
-        from_id = data["from_id"]
-
-        if defn.cardinality == "one-to-one":
-            existing = await get_children(
-                g.s,
-                parent_type=defn.from_type,
-                parent_id=from_id,
-                child_type=defn.to_type,
-                relation_type=rel_type,
-            )
-            if existing:
-                return {"allowed": False, "reason": "one-to-one relation already exists"}
-
-        return {"allowed": True}
-
-    _handlers["can-relate"] = _can_relate
-
+    bp, _handlers = create_action_blueprint("relations")
     return bp

relations/bp/data/routes.py

@@ -1,77 +1,14 @@
-"""Relations app data endpoints."""
+"""Relations app data endpoints.
+
+All queries are defined in ``relations/queries.sx``.
+"""
 from __future__ import annotations
 
-from quart import Blueprint, g, jsonify, request
+from quart import Blueprint
 
-from shared.infrastructure.data_client import DATA_HEADER
+from shared.infrastructure.query_blueprint import create_data_blueprint
 
 
 def register() -> Blueprint:
-    bp = Blueprint("data", __name__, url_prefix="/internal/data")
-
-    @bp.before_request
-    async def _require_data_header():
-        if not request.headers.get(DATA_HEADER):
-            return jsonify({"error": "forbidden"}), 403
-        from shared.infrastructure.internal_auth import validate_internal_request
-        if not validate_internal_request():
-            return jsonify({"error": "forbidden"}), 403
-
-    _handlers: dict[str, object] = {}
-
-    @bp.get("/<query_name>")
-    async def handle_query(query_name: str):
-        handler = _handlers.get(query_name)
-        if handler is None:
-            return jsonify({"error": "unknown query"}), 404
-        result = await handler()
-        return jsonify(result)
-
-    # --- get-children ---
-    async def _get_children():
-        """Return ContainerRelation children for a parent."""
-        from shared.services.relationships import get_children
-
-        parent_type = request.args.get("parent_type", "")
-        parent_id   = request.args.get("parent_id", type=int)
-        child_type  = request.args.get("child_type")
-        relation_type = request.args.get("relation_type")
-        if not parent_type or parent_id is None:
-            return []
-        rels = await get_children(g.s, parent_type, parent_id, child_type, relation_type=relation_type)
-        return [_serialize_rel(r) for r in rels]
-
-    _handlers["get-children"] = _get_children
-
-    # --- get-parents ---
-    async def _get_parents():
-        """Return ContainerRelation parents for a child."""
-        from shared.services.relationships import get_parents
-
-        child_type = request.args.get("child_type", "")
-        child_id = request.args.get("child_id", type=int)
-        parent_type = request.args.get("parent_type")
-        relation_type = request.args.get("relation_type")
-        if not child_type or child_id is None:
-            return []
-        rels = await get_parents(g.s, child_type, child_id, parent_type, relation_type=relation_type)
-        return [_serialize_rel(r) for r in rels]
-
-    _handlers["get-parents"] = _get_parents
-
+    bp, _handlers = create_data_blueprint("relations")
     return bp
-
-
-def _serialize_rel(r):
-    """Serialize a ContainerRelation to a dict."""
-    return {
-        "id": r.id,
-        "parent_type": r.parent_type,
-        "parent_id": r.parent_id,
-        "child_type": r.child_type,
-        "child_id": r.child_id,
-        "sort_order": r.sort_order,
-        "label": r.label,
-        "relation_type": r.relation_type,
-        "metadata": r.metadata_,
-    }

relations/queries.sx

@@ -0,0 +1,13 @@
+;; Relations service — inter-service data queries
+
+(defquery get-children (&key parent-type parent-id child-type relation-type)
+  "Return child relations for a parent."
+  (service "relations" "get-children"
+    :parent-type parent-type :parent-id parent-id
+    :child-type child-type :relation-type relation-type))
+
+(defquery get-parents (&key child-type child-id parent-type relation-type)
+  "Return parent relations for a child."
+  (service "relations" "get-parents"
+    :child-type child-type :child-id child-id
+    :parent-type parent-type :relation-type relation-type))

relations/services/__init__.py

@@ -4,3 +4,6 @@ from __future__ import annotations
 
 def register_domain_services() -> None:
     """Register services for the relations app."""
+    from shared.services.registry import services
+    from shared.services.relations_impl import SqlRelationsService
+    services.register("relations", SqlRelationsService())