chore: fix all biome lint errors

- Auto-fix string concatenation → template literals
- Remove unused imports
- Prefix unused function with underscore
- Format fixes across multiple files

packages/workflow-agent-react/package.json

@@ -1,7 +1,10 @@
 {
   "name": "@uncaged/workflow-agent-react",
   "version": "0.3.16",
-  "files": ["dist", "package.json"],
+  "files": [
+    "dist",
+    "package.json"
+  ],
   "type": "module",
   "main": "src/index.ts",
   "types": "src/index.ts",
@@ -25,4 +28,4 @@
   "peerDependencies": {
     "zod": "^4.0.0"
   }
-}
+}