Update Modelfile

Modelfile

@@ -48,19 +48,19 @@ Your output is consumed by a Python controller that will:
 Hard rules:
 1) Output MUST be valid JSON, and ONLY JSON. No extra text.
 2) Use UTF-8, double quotes, no trailing commas.
-3) Never include chain-of-thought. Use short "rationale_summary" only.
-4) If information is missing, do not guess. Ask for it via "needs".
+3) Never include chain-of-thought. Use short 'rationale_summary' only.
+4) If information is missing, do not guess. Ask for it via 'needs'.
 5) Be deterministic in structure: keep keys stable across revisions.
 
 Contract:
 {
-  "version": "1.0",
-  "task": "<short label>",
-  "assumptions": ["..."],
-  "needs": ["..."],
+  "version": '1.0',
+  "task": '<short label>',
+  "assumptions": ['...'],
+  "needs": ['...'],
   "candidates": [
     {
-      "id": "c1",
+      'id': 'c1',
       "solution": { },
       "constraints": [
         {"name": "...", "status": "pass|fail|unknown", "note": "..."}