Update dart agent to align with update in blueprints.

conformance/agent/direct_json/compiler.yaml

@@ -58,6 +58,9 @@
 # v1.0. A case states no version of its own: the version it runs under is the
 # one its catalog document declares.
 
+# A compile case checks the block on its own, as `validate_payload` does: a
+# surface that the block updates without creating is assumed to exist.
+
 - name: test_compile_json_message_list
   description: A well formed message list compiles to those messages.
   action: compile

conformance/agent/direct_json/decompiler.yaml

@@ -36,6 +36,9 @@
 # v1.0. A case states no version of its own: the version it runs under is the
 # one its catalog document declares.
 
+# A round trip checks the recompiled block on its own, as `validate_payload`
+# does: a surface that the block updates without creating is assumed to exist.
+
 - name: test_decompile_json_messages
   description: Messages are written back out as the JSON a model would have emitted, and compiling that returns them.
   action: decompile

conformance/agent/direct_json/response_parser.yaml

@@ -56,6 +56,9 @@
 # v1.0. A case states no version of its own: the version it runs under is the
 # one its catalog document declares.
 
+# A response is parsed as one chat turn, against a renderer that holds no
+# surfaces yet, so a case that updates a surface also creates it.
+
 # --- Unwrapping a response ---
 
 - name: test_unwrap_text_before_between_and_after_blocks
@@ -213,11 +216,15 @@
     catalog: "test_data/catalogs/simplified_catalog_v1_0.json"
   input: |-
     Here is the surface.
-    <a2ui-json>[{"version": "v1.0", "updateComponents": {"surfaceId": "s1", "components": [{"id": "root", "component": "Text", "text": "Hello"}]}}]</a2ui-json>
+    <a2ui-json>[{"version": "v1.0", "createSurface": {"surfaceId": "s1", "catalogId": "conformance/simplified"}}, {"version": "v1.0", "updateComponents": {"surfaceId": "s1", "components": [{"id": "root", "component": "Text", "text": "Hello"}]}}]</a2ui-json>
     Tell me if you want it changed.
   expect:
     - text: "Here is the surface."
     - a2ui:
+        - version: "v1.0"
+          createSurface:
+            surfaceId: "s1"
+            catalogId: "conformance/simplified"
         - version: "v1.0"
           updateComponents:
             surfaceId: "s1"