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

internal/promptdef/testdata/missing_id.yaml

@@ -0,0 +1,11 @@
+version: 1.0.0
+description: Missing ID
+inputs:
+  - name: transcript
+    required: true
+templates:
+  - role: system
+    content: Hello
+output_format: text
+validation:
+  validation_mode: none