Add Promptkit definition conformance coverage

testdata/promptkit-v0.9/prompts/complete-v1.yaml

@@ -0,0 +1,31 @@
+id: compat.complete
+version: "1.0.0"
+description: Exercise the complete Promptkit v0.9 prompt-definition surface.
+default_profile: custom-derived
+session_id: 'fixture-{{.topic}}'
+inputs:
+  - name: source
+    required: true
+    content_type: text/markdown
+    description: Source material rendered by a file-backed message.
+  - name: context
+    required: false
+    content_type: text/plain
+    description: Optional caller context.
+messages:
+  - role: developer
+    content: 'Use the topic {{.topic}}.'
+    cache_control:
+      type: ephemeral
+      ttl: 1h
+  - role: system
+    content_file: ./messages/complete.system.md
+  - role: user
+    content_file: ./messages/complete.user.md
+  - role: assistant
+    content: Return one JSON object.
+output:
+  format: json
+  validation_mode: json_schema
+  schema_path: complete.schema.json
+  repair_attempts: 2