Decouple all cross-app service calls to HTTP endpoints

Replace every direct cross-app services.* call with HTTP-based
communication: call_action() for writes, fetch_data() for reads.
Each app now registers only its own domain service.

Infrastructure:
- shared/infrastructure/actions.py — POST client for /internal/actions/
- shared/infrastructure/data_client.py — GET client for /internal/data/
- shared/contracts/dtos.py — dto_to_dict/dto_from_dict serialization

Action endpoints (writes):
- events: 8 handlers (ticket adjust, claim/confirm, toggle, adopt)
- market: 2 handlers (create/soft-delete marketplace)
- cart: 1 handler (adopt cart for user)

Data endpoints (reads):
- blog: 4 (post-by-slug/id, posts-by-ids, search-posts)
- events: 10 (pending entries/tickets, entries/tickets for page/order,
  entry-ids, associated-entries, calendars, visible-entries-for-period)
- market: 1 (marketplaces-for-container)
- cart: 1 (cart-summary)

Service registration cleanup:
- blog→blog+federation, events→calendar+federation,
  market→market+federation, cart→cart only,
  federation→federation only, account→nothing
- Stubs reduced to minimal StubFederationService

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

blog/bp/post/services/entry_associations.py

@@ -2,6 +2,9 @@ from __future__ import annotations
 
 from sqlalchemy.ext.asyncio import AsyncSession
 
+from shared.infrastructure.actions import call_action, ActionError
+from shared.infrastructure.data_client import fetch_data
+from shared.contracts.dtos import CalendarEntryDTO, dto_from_dict
 from shared.services.registry import services
 
 
@@ -18,10 +21,13 @@ async def toggle_entry_association(
     if not post:
         return False, "Post not found"
 
-    is_associated = await services.calendar.toggle_entry_post(
-        session, entry_id, "post", post_id,
-    )
-    return is_associated, None
+    try:
+        result = await call_action("events", "toggle-entry-post", payload={
+            "entry_id": entry_id, "content_type": "post", "content_id": post_id,
+        })
+        return result.get("is_associated", False), None
+    except ActionError as e:
+        return False, str(e)
 
 
 async def get_post_entry_ids(
@@ -32,7 +38,10 @@ async def get_post_entry_ids(
     Get all entry IDs associated with this post.
     Returns a set of entry IDs.
     """
-    return await services.calendar.entry_ids_for_content(session, "post", post_id)
+    raw = await fetch_data("events", "entry-ids-for-content",
+                           params={"content_type": "post", "content_id": post_id},
+                           required=False) or []
+    return set(raw)
 
 
 async def get_associated_entries(
@@ -45,12 +54,14 @@ async def get_associated_entries(
     Get paginated associated entries for this post.
     Returns dict with entries (CalendarEntryDTOs), total_count, and has_more.
     """
-    entries, has_more = await services.calendar.associated_entries(
-        session, "post", post_id, page,
-    )
+    raw = await fetch_data("events", "associated-entries",
+                           params={"content_type": "post", "content_id": post_id, "page": page},
+                           required=False) or {"entries": [], "has_more": False}
+    entries = [dto_from_dict(CalendarEntryDTO, e) for e in raw.get("entries", [])]
+    has_more = raw.get("has_more", False)
     total_count = len(entries) + (page - 1) * per_page
     if has_more:
-        total_count += 1  # at least one more
+        total_count += 1
 
     return {
         "entries": entries,

blog/bp/post/services/markets.py

@@ -8,6 +8,7 @@ from sqlalchemy.ext.asyncio import AsyncSession
 
 from shared.models.page_config import PageConfig
 from shared.contracts.dtos import MarketPlaceDTO
+from shared.infrastructure.actions import call_action, ActionError
 from shared.services.registry import services
 
 
@@ -48,8 +49,12 @@ async def create_market(sess: AsyncSession, post_id: int, name: str) -> MarketPl
         raise MarketError("Market feature is not enabled for this page. Enable it in page settings first.")
 
     try:
-        return await services.market.create_marketplace(sess, "page", post_id, name, slug)
-    except ValueError as e:
+        result = await call_action("market", "create-marketplace", payload={
+            "container_type": "page", "container_id": post_id,
+            "name": name, "slug": slug,
+        })
+        return MarketPlaceDTO(**result)
+    except ActionError as e:
         raise MarketError(str(e)) from e
 
 
@@ -58,4 +63,10 @@ async def soft_delete_market(sess: AsyncSession, post_slug: str, market_slug: st
     if not post:
         return False
 
-    return await services.market.soft_delete_marketplace(sess, "page", post.id, market_slug)
+    try:
+        result = await call_action("market", "soft-delete-marketplace", payload={
+            "container_type": "page", "container_id": post.id, "slug": market_slug,
+        })
+        return result.get("deleted", False)
+    except ActionError:
+        return False