fix(v3-ref-seller): rebase + restore mock_ad_server instrumentation + typed responses (PR #408 fix-pack)

Rebase onto main (53d8b8c) restored MockAdServer wiring on the 5
existing sales methods that PR #405 added. Apply _record(...) calls on
the 6 new methods this PR introduces (media_buys.list,
performance.feedback, creatives.formats, creatives.list,
accounts.sync, accounts.list) so storyboard runners polling
GET /_debug/traffic see real upstream activity.

Should-fix items:
- list_creatives count query — replaced full-table scan + len() with
  select(func.count()).select_from(CreativeRow). Test mock updated to
  expose .scalar() instead of .scalars().
- sync_creatives — typed SyncCreativeResult items instead of
  list[dict] with type:ignore.
- get_media_buys — typed MediaBuyWire items, dropping list[Any] dicts;
  re-validation through GetMediaBuysResponse keeps the response-shape
  guarantee.
- list_creative_formats — typed Format items.
- sync_accounts — dropped # type: ignore[union-attr] on
  brand.domain. Spec requires both brand and brand.domain (no None
  guard needed).

Test improvements (nits → should-fixes):
- test_list_accounts_runs_projection_on_every_row — converted manual
  setattr/try-finally patching to monkeypatch fixture; strengthened
  assertion to require billing_entity present then bank absent.
- Inline `from adcp.server import current_tenant` lifted to the
  module top of platform.py (one source of truth for the contextvar
  reader).

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

Author: bokelley

examples/v3_reference_seller/src/platform.py

@@ -56,6 +56,7 @@
     project_business_entity_for_response,
 )
 from adcp.decisioning.specialisms import SalesPlatform
+from adcp.server import current_tenant
 from adcp.types import (
     Account as AccountWire,
 )
@@ -76,7 +77,6 @@
     ListCreativeFormatsResponse,
     ListCreativesRequest,
     ListCreativesResponse,
-    MediaBuy as MediaBuyWire,
     Product,
     ProvidePerformanceFeedbackRequest,
     ProvidePerformanceFeedbackSuccessResponse,
@@ -88,7 +88,9 @@
     UpdateMediaBuyRequest,
     UpdateMediaBuySuccessResponse,
 )
-from adcp.server import current_tenant
+from adcp.types import (
+    MediaBuy as MediaBuyWire,
+)
 
 if TYPE_CHECKING:
     from sqlalchemy.ext.asyncio import async_sessionmaker
@@ -531,7 +533,13 @@ async def get_media_buys(
             "media_buys.list",
             {"account_id": ctx.account.id, "limit": limit, "offset": offset},
         )
-        return GetMediaBuysResponse(media_buys=media_buys)
+        # Pydantic re-validates each item against the response-specific
+        # ``MediaBuy`` shape. Passing the public-API ``MediaBuy``
+        # instances we built above ensures field drift surfaces here
+        # rather than at the wire boundary.
+        return GetMediaBuysResponse.model_validate(
+            {"media_buys": [m.model_dump(mode="python", exclude_none=True) for m in media_buys]}
+        )
 
     # ----- provide_performance_feedback ------------------------------------
 

examples/v3_reference_seller/tests/test_smoke_broadening.py

@@ -161,14 +161,17 @@ def test_list_accounts_projection_strips_bank_details() -> None:
 
 
 @pytest.mark.asyncio
-async def test_list_accounts_runs_projection_on_every_row() -> None:
+async def test_list_accounts_runs_projection_on_every_row(
+    monkeypatch: pytest.MonkeyPatch,
+) -> None:
     """End-to-end: drive ``V3ReferenceSeller.list_accounts`` against a
     mocked session whose row carries bank details and assert no
     response account leaks them. This is the platform-level guarantee
     the spec requires.
     """
     from unittest.mock import AsyncMock, MagicMock
 
+    import src.platform as platform_module
     from src.models import Account as AccountRow
     from src.models import BuyerAgent as BuyerAgentRow
     from src.platform import V3ReferenceSeller
@@ -220,46 +223,38 @@ async def test_list_accounts_runs_projection_on_every_row() -> None:
     session.execute = AsyncMock(side_effect=[ba_result, accounts_result])
     sessionmaker = MagicMock(return_value=session)
 
-    # Mock the tenant contextvar reader.
-    import src.platform as platform_module
-
-    from adcp.server import current_tenant as _real
-
+    # Patch the tenant contextvar reader where the platform looks it up.
     class _Tenant:
         id = "t_acme"
 
-    has_current = hasattr(platform_module, "current_tenant")
-    original = platform_module.current_tenant if has_current else _real
-    # Patch the import inside the method by patching at module level.
-    import adcp.server as server_module
-
-    monkeypatched = lambda: _Tenant()  # noqa: E731
-    setattr(server_module, "current_tenant", monkeypatched)
-    try:
-        platform = V3ReferenceSeller(sessionmaker=sessionmaker)
-
-        ctx = RequestContext(
-            buyer_agent=BuyerAgent(
-                agent_url="https://signed-buyer.example/",
-                display_name="Signed Buyer",
-                status="active",
-                billing_capabilities=frozenset({"operator", "agent"}),
-            ),
-            account=None,
-        )
-        req = ListAccountsRequest()
-        resp = await platform.list_accounts(req, ctx)
-    finally:
-        setattr(server_module, "current_tenant", original)
+    monkeypatch.setattr(platform_module, "current_tenant", lambda: _Tenant())
+
+    platform = V3ReferenceSeller(sessionmaker=sessionmaker)
+
+    ctx = RequestContext(
+        buyer_agent=BuyerAgent(
+            agent_url="https://signed-buyer.example/",
+            display_name="Signed Buyer",
+            status="active",
+            billing_capabilities=frozenset({"operator", "agent"}),
+        ),
+        account=None,
+    )
+    req = ListAccountsRequest()
+    resp = await platform.list_accounts(req, ctx)
 
     payload = resp.model_dump(mode="json", exclude_none=True)
     assert payload["accounts"], "expected at least one account in response"
     for acct in payload["accounts"]:
-        # The headline guarantee — bank MUST NOT echo on the wire.
-        if "billing_entity" in acct:
-            assert (
-                "bank" not in acct["billing_entity"]
-            ), f"bank details leaked on list_accounts response: {acct}"
+        # The 3.1-readiness headline: billing_entity SHOULD echo on the
+        # wire (the spec requires it for invoicing visibility) — but
+        # the write-only ``bank`` block MUST NOT.
+        assert (
+            "billing_entity" in acct
+        ), f"billing_entity missing from list_accounts response: {acct}"
+        assert (
+            "bank" not in acct["billing_entity"]
+        ), f"bank details leaked on list_accounts response: {acct}"
 
 
 # ---------------------------------------------------------------------------
@@ -315,8 +310,10 @@ def _hydrate_rows() -> list[CreativeRow]:
         return list(written_rows)
 
     def _list_session_factory() -> MagicMock:
+        # The platform issues ``select(func.count()).select_from(...)``
+        # for total, then a paged ``select(CreativeRow)`` for rows.
         count_result = MagicMock()
-        count_result.scalars = MagicMock(side_effect=lambda: iter(_hydrate_rows()))
+        count_result.scalar = MagicMock(side_effect=lambda: len(_hydrate_rows()))
         page_result = MagicMock()
         page_result.scalars = MagicMock(side_effect=lambda: iter(_hydrate_rows()))
         s = MagicMock()