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-service.yaml

@@ -0,0 +1,11 @@
+apiVersion: v1
+kind: Service
+metadata:
+  name: audit-log-collector
+  namespace: observability
+spec:
+  selector:
+    app: audit-log-collector
+  ports:
+    - port: 80
+      targetPort: 8888