refactor(couchdb): move raw manifests to templates/ subdir

Per Tony's recommendation — eliminates the explicit include filter.
New manifests go in templates/ and are picked up automatically by ArgoCD.
No filter to update when adding future resources.

Moved: namespace.yaml, externalsecret.yaml, ingress-public.yaml -> templates/

cluster/applications/couchdb/templates/externalsecret.yaml

@@ -0,0 +1,36 @@
+apiVersion: external-secrets.io/v1beta1
+kind: ExternalSecret
+metadata:
+  name: couchdb-credentials
+  namespace: couchdb
+  labels:
+    app.kubernetes.io/name: couchdb
+    app.kubernetes.io/part-of: mk-labs
+spec:
+  refreshInterval: 1h
+  secretStoreRef:
+    kind: ClusterSecretStore
+    name: onepassword-connect
+  target:
+    name: couchdb-admin
+    creationPolicy: Owner
+    template:
+      engineVersion: v2
+      data:
+        adminUsername: "admin"
+        adminPassword: "{{ .adminPassword }}"
+        cookieAuthSecret: "{{ .cookieAuthSecret }}"
+        erlangCookie: "{{ .erlangCookie }}"
+  data:
+    - secretKey: adminPassword
+      remoteRef:
+        key: couchdb
+        property: admin-password
+    - secretKey: cookieAuthSecret
+      remoteRef:
+        key: couchdb
+        property: cookie-auth-secret
+    - secretKey: erlangCookie
+      remoteRef:
+        key: couchdb
+        property: erlang-cookie