debug: test same-namespace ImagePolicy for Setters resolution

Every official Flux example uses the same namespace for ImagePolicy and
ImageUpdateAutomation; our setup splits them (ImagePolicy in hello-app,
ImageUpdateAutomation in flux-system). Testing whether that cross-namespace
split is the actual blocker, despite being documented as supported.

Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01Y4YNpuC2bgT224suQLLJ7B

apps/hello-app/setter-test.yaml

@@ -1,4 +1,22 @@
 # Throwaway diagnostic file - delete once the Setters investigation is done.
+# Testing whether a same-namespace-as-ImageUpdateAutomation ImagePolicy
+# resolves differently than the existing cross-namespace one.
+apiVersion: image.toolkit.fluxcd.io/v1
+kind: ImagePolicy
+metadata:
+  name: hello-app-samens-test
+  namespace: flux-system
+spec:
+  imageRepositoryRef:
+    name: hello-app
+    namespace: hello-app
+  policy:
+    numerical:
+      order: asc
+  filterTags:
+    pattern: '^main-[a-f0-9]+-(?P<ts>\d+)$'
+    extract: '$ts'
+---
 apiVersion: v1
 kind: ConfigMap
 metadata:
@@ -6,3 +24,4 @@ metadata:
   namespace: hello-app
 data:
   image: git.boglabob.com/codegit/hello-app:latest # {"$imagepolicy": "hello-app:hello-app"}
+  image_samens: git.boglabob.com/codegit/hello-app:latest # {"$imagepolicy": "flux-system:hello-app-samens-test"}