fix(protocol): align rc.10 codegen artifacts and the build_creative task type

Follow-ups surfaced by the full test gate after the rc.10 regen:

- post_generate_fixes.restore_format_asset_numbered_aliases: detect the
  repeatable asset group by its Literal['repeatable_group'] annotation, not
  only by an already-injected default. The fix runs before
  inject_literal_discriminator_defaults, and rc.10's codegen emits the
  discriminator without a default — so the prior Constant-value check missed
  the class and the Assets94 back-compat alias was dropped, breaking
  tests/test_forward_compat_assets.py.
- decisioning.webhook_emit.SPEC_WEBHOOK_TASK_TYPES: add build_creative. The
  rc.10 task-type enum widened to include it and BuildCreativeRequest now
  carries push_notification_config, so it is an async webhook-emitting task.
  The constant is pinned to the on-disk enum by a CI test.
- tests/fixtures/public_api_snapshot.json: regenerate for the intended
  GeoPostalArea -> PostalArea public rename.

Note for the TS SDK: bump its SPEC_WEBHOOK_TASK_TYPES for build_creative in
lockstep (cross-repo, out of scope here).

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>

Author: bokelley

scripts/post_generate_fixes.py

@@ -2150,7 +2150,19 @@ def restore_format_asset_numbered_aliases() -> None:
                 continue
             if not isinstance(stmt.target, ast.Name) or stmt.target.id != "item_type":
                 continue
-            if isinstance(stmt.value, ast.Constant) and stmt.value.value == "repeatable_group":
+            # Match the discriminator either by its already-injected default
+            # value or by its ``Literal['repeatable_group']`` annotation. The
+            # default is added by ``inject_literal_discriminator_defaults``,
+            # which runs after this fix in the registry — so when the codegen
+            # emits the discriminator without a default (rc.10 shape), only the
+            # annotation is available here.
+            has_const_default = (
+                isinstance(stmt.value, ast.Constant) and stmt.value.value == "repeatable_group"
+            )
+            has_literal_annotation = (
+                _extract_single_literal_value(stmt.annotation) == "repeatable_group"
+            )
+            if has_const_default or has_literal_annotation:
                 repeatable_class = node.name
                 break
         if repeatable_class is not None:

src/adcp/decisioning/webhook_emit.py

@@ -74,6 +74,7 @@
         "create_media_buy",
         "update_media_buy",
         "media_buy_delivery",
+        "build_creative",
         "sync_creatives",
         "activate_signal",
         "get_products",

src/adcp/types/_generated.py

@@ -10,7 +10,7 @@
 DO NOT EDIT MANUALLY.
 
 Generated from: https://github.com/adcontextprotocol/adcp/tree/main/schemas
-Generation date: 2026-06-07 22:49:28 UTC
+Generation date: 2026-06-07 23:11:03 UTC
 """
 
 # ruff: noqa: E501, I001
@@ -845,6 +845,7 @@
     Assets51,
     Assets52,
     Assets53,
+    Assets94,
     BaseGroupAsset,
     BaseIndividualAsset,
     Dimensions,
@@ -2232,6 +2233,7 @@
     "Assets51",
     "Assets52",
     "Assets53",
+    "Assets94",
     "AssignedPackage",
     "Assignment",
     "Assignments",

src/adcp/types/generated_poc/core/format.py

@@ -1,6 +1,6 @@
 # generated by datamodel-codegen:
 #   filename:  core/format.json
-#   timestamp: 2026-06-07T22:46:16+00:00
+#   timestamp: 2026-06-07T23:07:52+00:00
 
 from __future__ import annotations
 
@@ -629,3 +629,7 @@ class Format(AdCPBaseModel):
             description="**DEPRECATED in 3.1. Removed at 4.0.** Use `v1_format_ref` on the v2 `ProductFormatDeclaration` instead — the seller authors a v2 declaration (in `Product.format_options` or `creative.supported_formats`) and links it back to this v1 format via `v1_format_ref: { agent_url, id }`. The directional link from v2 → v1 is the same fact as `canonical_parameters` without the parallel-shape drift surface (v1 file and `canonical_parameters` were two declarations of the same thing; hand-authored, drifting silently).\n\nMigration: every seller currently authoring `canonical_parameters` SHOULD migrate to authoring a v2 declaration on the corresponding product (or capability) with `v1_format_ref` pointing back at this v1 format. v1 files become pure v1 again — no v2-shape mirroring.\n\n*Legacy behavior, retained for 3.1–3.x backward compatibility:* When `canonical` is set, this field carries the full ProductFormatDeclaration that the SDK projects this v1 format into. The `format_kind` MUST equal the `canonical` field value (validators enforce). When set, this is the authoritative source for SDK v1→v2 projection — the registry's structural-match parameter inference is bypassed. SDKs reading 3.1 catalogs MUST continue to honor `canonical_parameters` when present; 4.0+ SDKs MAY reject the field. New code SHOULD NOT emit this field.\n\n**Drift contract (still normative while supported).** Hand-authored `canonical_parameters` MUST satisfy the *narrows* relation against this v1 format's `requirements` and `assets[*]` shape (see canonical-formats.mdx 'Narrows — formal definition'). SDKs that read this v1 file SHOULD lint-time check the equivalence at build/load and emit `FORMAT_PROJECTION_FAILED` if the two disagree.",
         ),
     ] = None
+
+
+# Backward compatibility for the pre-beta3 generated repeatable group name.
+Assets94 = Assets39

tests/fixtures/public_api_snapshot.json

@@ -733,7 +733,6 @@
     "GeneratedTaskStatus",
     "GeoCountry",
     "GeoMetro",
-    "GeoPostalArea",
     "GeoRegion",
     "GetAccountFinancialsErrorResponse",
     "GetAccountFinancialsRequest",
@@ -919,6 +918,7 @@
     "PolicyHistory",
     "PolicyRevision",
     "PolicySummary",
+    "PostalArea",
     "Preview",
     "PreviewCreativeBatchResponse",
     "PreviewCreativeFormatRequest",