Merge pull request '新增 Nexus 统一制品仓库 POC' (#103) from feat/nexus-poc into main

Reviewed-on: #103

clusters/homelab/README.md

@@ -53,4 +53,6 @@ sudo k3s kubectl -n flux-system get gitrepositories,kustomizations
 - SPIRE 已按 hardened chart 内部 fork `0.30.2-ddupan.1`（基于上游 `0.30.2`，SPIRE
   `1.15.3`）声明，使用共享
   PostgreSQL 与独立 signing-key PVC；首次上线和 OpenBao JWT-SVID PoC 尚待合并后验证；
+- Nexus Repository CE POC 已加入 GitOps 声明，计划验证 Ansible Galaxy、Go Modules 与
+  OCI/BuildKit 缓存；尚未部署或完成现场验收，现有 zot 保持不变；
 - root Kustomization 与所有 brownfield 子 Kustomization 继续保持 `prune: false`。

clusters/homelab/apps/nexus.yaml

@@ -0,0 +1,22 @@
+apiVersion: kustomize.toolkit.fluxcd.io/v1
+kind: Kustomization
+metadata:
+  name: nexus
+  namespace: flux-system
+spec:
+  dependsOn:
+    - name: envoy-gateway
+    - name: openebs
+  healthChecks:
+    - apiVersion: apps/v1
+      kind: Deployment
+      name: nexus
+      namespace: nexus
+  interval: 10m
+  path: ./apps/nexus
+  prune: false
+  sourceRef:
+    kind: GitRepository
+    name: flux-system
+  timeout: 15m
+  wait: true

clusters/homelab/kustomization.yaml

@@ -15,3 +15,4 @@ resources:
   - apps/spire.yaml
   - apps/observability.yaml
   - apps/zot.yaml
+  - apps/nexus.yaml