test(e2e): assert referenced-data companions by their un-prefixed name

referenced.CompanionName returns the source object's own name when it is a
valid DNS subdomain within the length budget (the kind argument is ignored),
so the companions materialize as app-config and app-secret, not
configmap.app-config and secret.app-secret. The first CI run confirmed this:
the referenced-data-delete-cascade suite (source names gc-test-config /
gc-test-secret) found its un-prefixed companions, while referenced-data-mounts
timed out looking for the prefixed names. Correct the assertions and the
naming-convention note in the README.

Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>

Author: scotwells

test/e2e/referenced-data-mounts/README.md

@@ -10,7 +10,7 @@ The test covers Hops 1–5 of the federated delivery chain:
 | Hop | Cluster | What is asserted |
 |-----|---------|-----------------|
 | 1 | control-plane | Source ConfigMap + Secret created in the project namespace |
-| 2 | control-plane | Companion `configmap.app-config` + `secret.app-secret` appear in `ns-{project-uid}` with `compute.datumapis.com/referenced-data: "true"`; WD carries `expected-referenced-data` annotation; WD condition `ReferencedDataReady=True` |
+| 2 | control-plane | Companion `app-config` + `app-secret` appear in `ns-{project-uid}` with `compute.datumapis.com/referenced-data: "true"`; WD carries `expected-referenced-data` annotation; WD condition `ReferencedDataReady=True` |
 | 3 | downstream (Karmada hub) | Companion ConfigMap + Secret present in `ns-{project-uid}` on the hub; WD carries the annotation; `PropagationPolicy city-dfw` has ConfigMap and Secret resource selectors |
 | 4 | pop-dfw (cell) | WD + companions propagated to the cell in `ns-{project-uid}` |
 | 5 | pop-dfw (cell) | Instance `test-refdata-wd-0` exists; `ReferencedData` scheduling gate cleared; `ReferencedDataReady=True` condition set |
@@ -76,11 +76,13 @@ operators from the real overlays. Points worth knowing:
 
 ## Companion naming convention
 
-The `ReferencedDataController` derives companion names deterministically:
+The `ReferencedDataController` derives companion names deterministically. When
+the source name is already a valid DNS subdomain within the length budget, the
+companion keeps that name unchanged (kind is not prefixed):
 
 | Source | Companion name |
 |--------|---------------|
-| `ConfigMap/app-config` | `configmap.app-config` |
-| `Secret/app-secret` | `secret.app-secret` |
+| `ConfigMap/app-config` | `app-config` |
+| `Secret/app-secret` | `app-secret` |
 
 These names are asserted directly in the test steps.

test/e2e/referenced-data-mounts/chainsaw-test.yaml

@@ -66,7 +66,7 @@ spec:
 
   - name: assert-companion-configmap-on-hub
     description: |
-      Assert the ReferencedDataController materialised companion configmap.app-config
+      Assert the ReferencedDataController materialised companion app-config
       in ns-{project-uid} on the Karmada hub (downstream cluster).
       Companions are written to the hub namespace, NOT the control-plane namespace.
     cluster: downstream
@@ -86,13 +86,13 @@ spec:
           kind: ConfigMap
           metadata:
             namespace: ($companionNS)
-            name: configmap.app-config
+            name: app-config
             labels:
               compute.datumapis.com/referenced-data: "true"
 
   - name: assert-companion-secret-on-hub
     description: |
-      Assert the ReferencedDataController materialised companion secret.app-secret
+      Assert the ReferencedDataController materialised companion app-secret
       in ns-{project-uid} on the Karmada hub (downstream cluster).
       Companions are written to the hub namespace, NOT the control-plane namespace.
     cluster: downstream
@@ -112,7 +112,7 @@ spec:
           kind: Secret
           metadata:
             namespace: ($companionNS)
-            name: secret.app-secret
+            name: app-secret
             labels:
               compute.datumapis.com/referenced-data: "true"
 
@@ -180,7 +180,7 @@ spec:
           kind: ConfigMap
           metadata:
             namespace: ($downstreamNS)
-            name: configmap.app-config
+            name: app-config
             labels:
               compute.datumapis.com/referenced-data: "true"
     - assert:
@@ -191,7 +191,7 @@ spec:
           kind: Secret
           metadata:
             namespace: ($downstreamNS)
-            name: secret.app-secret
+            name: app-secret
             labels:
               compute.datumapis.com/referenced-data: "true"
 
@@ -269,7 +269,7 @@ spec:
           kind: ConfigMap
           metadata:
             namespace: ($downstreamNS)
-            name: configmap.app-config
+            name: app-config
             labels:
               compute.datumapis.com/referenced-data: "true"
     - assert:
@@ -279,7 +279,7 @@ spec:
           kind: Secret
           metadata:
             namespace: ($downstreamNS)
-            name: secret.app-secret
+            name: app-secret
             labels:
               compute.datumapis.com/referenced-data: "true"