C0: alloy — bump kustomization tags to main-branch SHA

Per the build-container-image squash-merge convention, rebuild alloy v1.16.0
container images from the main SHA (9564435) and update the three alloy
kustomizations to reference :v1.16.0-9564435[-nix] instead of the branch
SHA :v1.16.0-26a3ab5[-nix] left over from #345.

Both images were rebuilt locally on gilbert (dagger) and ringtail (nix)
because indri is still under heavy macOS memory-compressor pressure (see
separate ticket); CI on indri can't reliably run the dagger publish step.

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

argocd/manifests/alloy-k8s/kustomization.yaml

@@ -10,7 +10,7 @@ resources:
 
 images:
   - name: registry.ops.eblu.me/blumeops/alloy
-    newTag: v1.16.0-26a3ab5
+    newTag: v1.16.0-9564435
 
 configMapGenerator:
   - name: alloy-config

argocd/manifests/alloy-ringtail/kustomization.yaml

@@ -10,7 +10,7 @@ resources:
 
 images:
   - name: registry.ops.eblu.me/blumeops/alloy
-    newTag: v1.16.0-26a3ab5-nix
+    newTag: v1.16.0-9564435-nix
 
 configMapGenerator:
   - name: alloy-config

argocd/manifests/alloy-tracing-ringtail/kustomization.yaml

@@ -9,7 +9,7 @@ resources:
 
 images:
   - name: registry.ops.eblu.me/blumeops/alloy
-    newTag: v1.16.0-26a3ab5-nix
+    newTag: v1.16.0-9564435-nix
 
 configMapGenerator:
   - name: alloy-tracing-config

docs/changelog.d/+alloy-main-sha-rebuild.infra.md

@@ -0,0 +1,5 @@
+Rebuild and retag alloy v1.16.0 container images from the main-branch SHA
+following the squash-merge of #345, per the build-container-image
+squash-merge convention. Both images (`registry.ops.eblu.me/blumeops/alloy`)
+now reference `9564435` rather than the branch SHA `26a3ab5`, restoring
+source traceability after branch cleanup.