refactor: one self-contained folder per platform service

Each platform/apps/<service>/ now holds its own application.yaml
(multi-source: chart + values + raw-manifest extras), values.yaml, and
any extra manifests (HTTPRoute, RBAC, ClusterSecretStore) together,
replacing the split apps/*.yaml + manifests/*/ + separate *-config
Application pattern.

Root platform-app.yaml now recurses platform/apps/*/application.yaml
only. Extras get a resource-level sync-wave (1) so they still land
after their service's Helm chart within the same Application sync.

Also adds an HTTPRoute for vault (vault.fireflylab.local) - exposed
same as every other service here, accepted as LAN-only exposure.

platform/apps/vault/application.yaml

@@ -0,0 +1,34 @@
+apiVersion: argoproj.io/v1alpha1
+kind: Application
+metadata:
+  name: vault
+  namespace: argocd
+  annotations:
+    argocd.argoproj.io/sync-wave: "0"
+spec:
+  project: default
+  sources:
+    - repoURL: https://helm.releases.hashicorp.com
+      chart: vault
+      targetRevision: "0.30.0"  # TODO: verify latest via `helm search repo hashicorp/vault --versions`
+      helm:
+        valueFiles:
+          - $values/platform/apps/vault/values.yaml
+    - repoURL: https://gitea.fireflylab.cc/duynguyen/cluster-platform.git
+      targetRevision: main
+      ref: values
+    - repoURL: https://gitea.fireflylab.cc/duynguyen/cluster-platform.git
+      targetRevision: main
+      path: platform/apps/vault
+      directory:
+        exclude: "{application.yaml,values.yaml}"
+  destination:
+    server: https://kubernetes.default.svc
+    namespace: vault
+  syncPolicy:
+    automated:
+      prune: true
+      selfHeal: true
+    syncOptions:
+      - CreateNamespace=true
+      - SkipDryRunOnMissingResource=true

platform/apps/vault/httproute.yaml

@@ -0,0 +1,22 @@
+apiVersion: gateway.networking.k8s.io/v1
+kind: HTTPRoute
+metadata:
+  name: vault
+  namespace: vault
+  annotations:
+    argocd.argoproj.io/sync-wave: "1"
+spec:
+  parentRefs:
+    - name: envoy-gateway
+      namespace: envoy-gateway-system
+  hostnames:
+    - "vault.fireflylab.local"
+  rules:
+    - matches:
+        - path:
+            type: PathPrefix
+            value: /
+      backendRefs:
+        # verify with: kubectl get svc -n vault  (UI served on same port as API when ui.enabled)
+        - name: vault
+          port: 8200

platform/apps/vault/values.yaml

@@ -0,0 +1,15 @@
+server:
+  dataStorage:
+    enabled: true
+    storageClass: nfs-delete
+    size: 10Gi
+  standalone:
+    enabled: true
+  ha:
+    enabled: false
+
+ui:
+  enabled: true
+
+injector:
+  enabled: true