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-app.yaml

@@ -9,6 +9,9 @@ spec:
     repoURL: https://gitea.fireflylab.cc/duynguyen/cluster-platform.git
     targetRevision: main
     path: platform/apps
+    directory:
+      recurse: true
+      include: "*/application.yaml"
   destination:
     server: https://kubernetes.default.svc
     namespace: argocd