Add artifact-backed story prompt for SLE-V2.1

model.cra

@@ -1,3 +1,3 @@
 version https://git-lfs.github.com/spec/v1
-oid sha256:10c8a7eae3a89523fe7f322771ffdb88074c7d5eb45021898eb398d8ec7d5790
-size 173913074
+oid sha256:a391b7cdc5487c26b3245e7cd80044aec6f6bd49790c800c7cd4c3f9a15e9b10
+size 173916316

sle_v2_1_release_metrics.json

@@ -30,6 +30,11 @@
   "readiness_success": true,
   "release_name": "SLE-V2.1-\u03a912K-LX",
   "release_smoke_success": true,
+  "story_prompt_success": true,
+  "story_prompt_text": "Luma found a quiet bell, listened, and opened the moonlit gate.",
+  "story_prompt_tool_path": [
+    "fact.lookup"
+  ],
   "system_instruction_success": true,
   "system_instruction_tool_path": [
     "fact.lookup"