feat: add promptfoo eval harness for agent quality scoring (#371)

Adds promptfoo eval harness for agent quality scoring. LLM-as-judge system scoring task completion, instruction adherence, identity consistency, deliverable quality, and safety. Includes tests.

evals/tsconfig.json

@@ -0,0 +1,15 @@
+{
+  "compilerOptions": {
+    "target": "ES2022",
+    "module": "commonjs",
+    "moduleResolution": "node",
+    "esModuleInterop": true,
+    "strict": true,
+    "outDir": "dist",
+    "rootDir": ".",
+    "resolveJsonModule": true,
+    "declaration": false
+  },
+  "include": ["scripts/**/*.ts"],
+  "exclude": ["node_modules", "dist"]
+}