Complete eval correctness hardening

Add Vally 0.13 all-error compatibility, a practical net-win floor, objective completion criteria, and CI fault-injection coverage.

Co-authored-by: Copilot App <223556219+Copilot@users.noreply.github.com>

Copilot-Session: 1c6716a2-172b-461a-adb5-127b1ba7e96b

.github/workflows/evaluation-workflow-tests.yml

@@ -8,6 +8,7 @@ on:
       - ".github/workflows/evaluation-workflow-tests.yml"
       - "eng/evaluation-tools/**"
       - "eng/evaluation/test_token_failover.py"
+      - "eng/vally-adapter/**"
   push:
     branches: [main]
     paths:
@@ -16,12 +17,30 @@ on:
       - ".github/workflows/evaluation-workflow-tests.yml"
       - "eng/evaluation-tools/**"
       - "eng/evaluation/test_token_failover.py"
+      - "eng/vally-adapter/**"
   workflow_dispatch:
 
 permissions:
   contents: read
 
 jobs:
+  vally-adapter:
+    runs-on: ubuntu-latest
+    timeout-minutes: 10
+    steps:
+      - name: Checkout repository
+        uses: actions/checkout@9c091bb21b7c1c1d1991bb908d89e4e9dddfe3e0 # v6
+        with:
+          persist-credentials: false
+
+      - name: Setup Node.js
+        uses: actions/setup-node@820762786026740c76f36085b0efc47a31fe5020 # v7.0.0
+        with:
+          node-version: 22
+
+      - name: Run adapter fault-injection and report tests
+        run: node --test eng/vally-adapter/*.test.mjs
+
   evaluation-tools:
     runs-on: ubuntu-latest
     timeout-minutes: 10