feat(scripts): add detect-url-changes change-detection step

Co-authored-by: Nasyarobby Putra <nasyarobby@gmail.com>

packages/server/workflows/default/detect-example-changes.yaml

@@ -0,0 +1,18 @@
+name: detect example.com changes
+description: |
+  Fetch example.com, fingerprint the response, and report whether it changed
+  since the previous run. Uses detect-url-changes with a transform that builds
+  a human-readable message into ctx.data.message.
+scripts:
+  - script: detect-url-changes.js
+    config:
+      url: https://example.com/
+      outputVar: message
+      transform: >
+        data.hasChanges
+          ? "example.com changed (fingerprint " & data.fingerprint & ")"
+          : "example.com unchanged since " & data.fingerprintAt
+triggers:
+  - type: HTTP
+    method: POST
+    path: /detect-example