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>

account/bp/actions/routes.py

@@ -1,63 +1,33 @@
 """Account app action endpoints.
 
-Exposes write operations at ``/internal/actions/<action_name>`` for
-cross-app callers (blog webhooks) via the internal action client.
+All actions remain as Python fallbacks (local service imports).
 """
 from __future__ import annotations
 
-from quart import Blueprint, g, jsonify, request
+from quart import Blueprint, g, request
 
-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, _handlers = create_action_blueprint("account")
 
-    @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
-
-    # --- ghost-sync-member ---
     async def _ghost_sync_member():
-        """Sync a single Ghost member into db_account."""
         data = await request.get_json()
         ghost_id = data.get("ghost_id")
         if not ghost_id:
             return {"error": "ghost_id required"}, 400
-
         from services.ghost_membership import sync_single_member
         await sync_single_member(g.s, ghost_id)
         return {"ok": True}
 
     _handlers["ghost-sync-member"] = _ghost_sync_member
 
-    # --- ghost-push-member ---
     async def _ghost_push_member():
-        """Push a local user's membership data to Ghost."""
         data = await request.get_json()
         user_id = data.get("user_id")
         if not user_id:
             return {"error": "user_id required"}, 400
-
         from services.ghost_membership import sync_member_to_ghost
         result_id = await sync_member_to_ghost(g.s, int(user_id))
         return {"ok": True, "ghost_id": result_id}