Refactor: load execution profiles from YAML and split prompt definitions into promptdef repository

internal/promptdef/testdata/json_schema_missing_path.yaml

@@ -0,0 +1,11 @@
+id: json-schema-missing-path
+version: "1.0.0"
+inputs:
+  - name: transcript
+    required: true
+templates:
+  - role: user
+    content: "Return JSON"
+output_format: json
+validation:
+  validation_mode: json_schema