Establish prompt engineering baseline with Gold Standard tests

- introduce Gold Standard evaluation corpus
- document decision taxonomy
- define prompt-engineering methodology
- add regression workflow
- establish Prompt Version 2 baseline
- validate decision_simple, decision_deferred and decision_none

tests/gold/todo_negative/expected.json

@@ -0,0 +1,22 @@
+{
+  "facts": [
+    {
+      "fact": "The customer export takes longer than Paula expected.",
+      "evidence": "Paula: The customer export takes longer than I expected."
+    },
+    {
+      "fact": "There is no owner for the customer export issue for now.",
+      "evidence": "Paula: Right, no owner for now."
+    }
+  ],
+  "decisions": [
+    {
+      "decision": "The customer export issue will stay on the risk list for now.",
+      "evidence": "Sam: Then let's just keep it on the risk list. Paula: Right, no owner for now."
+    }
+  ],
+  "todos": [],
+  "questions": [],
+  "positions": [],
+  "technical": []
+}