_resolve_config_files now generates a v3-compatible YAML (type: llm)
when serialising a built-in actor's config_blob, so ReactiveConfigParser
can build a proper ReactiveConfig with routes and run_single_shot()
invokes the LLM and returns its response.

Root cause: yaml.safe_dump(config_blob) produced a flat dict without a
'type' field. ReactiveConfigParser._build() could not recognise it as a
v3 actor (_is_v3_format() returned False), so it created an empty
ReactiveConfig with no routes. run_single_shot() then fell through to
the RxPY stream path which has no subscribers and silently returned .

Fix: added _build_v3_yaml_from_blob() which synthesises a minimal
type: llm YAML from the blob's provider and model fields. This allows
_build_from_v3() to create a proper ReactiveConfig with a synthesised
graph route, so run_single_shot() can find the route and invoke the LLM.

The condition checks for provider+model without type to target only
built-in provider-registry blobs; custom actors with yaml_text or
type-bearing config_blobs are unaffected.

ISSUES CLOSED: #10861

@@ -52,6 +53,44 @@ def _sanitize_name(name: str) -> str:
     return "".join(c for c in name if c.isprintable())

@@ -0,0 +15,4 @@
+from behave.runner import Context  # type: ignore[import-untyped]
+
+from cleveragents.cli.commands._resolve_actor import resolve_config_files
+

@@ -0,0 +102,4 @@
+
+@then("the resulting YAML file contains the provider and model for tdd-10861")
+def step_then_yaml_contains_provider_model(context: Context) -> None:
+    """Assert the synthesised YAML contains the correct provider and model."""

@@ -55,0 +69,4 @@
+
+    Returns:
+        A YAML string in v3 type: llm format that the reactive config
+        parser can consume to produce a working single-agent graph route.

@@ -112,2 +142,2 @@
-            )
-            raise typer.Exit(code=2) from None
+        # Fix #10861: built-in actors have a config_blob with provider
+        # and model but no type field. Serialising this blob as-is