Add audit-log-collector (Fluent Bit) in observability

Receives the http-log plugin's POSTs and dumps each record as a JSON
line to a PVC-backed file. Applied directly (kubectl), same as Jaeger
in this namespace — not Flux-managed yet.

observability/audit-log-collector-pvc.yaml

@@ -0,0 +1,11 @@
+apiVersion: v1
+kind: PersistentVolumeClaim
+metadata:
+  name: audit-log-collector-data
+  namespace: observability
+spec:
+  accessModes:
+    - ReadWriteOnce
+  resources:
+    requests:
+      storage: 1Gi