feat(k8s): add K8s manifests for all homelab services

traefik, gitea, adguard, nextcloud, errorpages, homepages,
uptime-kuma, kener, checkmk, headscale, dockmon, metube,
downtify, portainer, netronome, userbot

Includes Helm values, deployments, services, ingress routes,
configmaps, secrets (placeholders), postgres statefulsets,
kustomize overlays, and Traefik dynamic configuration.

gitea/k8s/gitea.yaml

@@ -0,0 +1,71 @@
+apiVersion: v1
+kind: Service
+metadata:
+  name: gitea-service
+  namespace: gitea
+spec:
+  selector:
+    app: gitea
+  ports:
+  - port: 3000
+    name: http
+    targetPort: 3000
+  - port: 2221
+    name: ssh
+    targetPort: 2221
+---
+apiVersion: apps/v1
+kind: Deployment
+metadata:
+  name: gitea-deployment
+  namespace: gitea
+spec:
+  replicas: 1
+  selector:
+    matchLabels:
+      app: gitea
+  template:
+    metadata:
+      labels:
+        app: gitea
+    spec:
+      containers:
+      - name: gitea
+        image: docker.gitea.com/gitea:1.26
+        envFrom:
+        - configMapRef:
+            name: gitea-config
+        - secretRef:
+            name: gitea-secrets
+        ports:
+        - containerPort: 3000
+          name: http
+        - containerPort: 2221
+          name: ssh
+        volumeMounts:
+        - name: gitea-data
+          mountPath: /data
+        resources:
+          requests:
+            memory: "512Mi"
+            cpu: "500m"
+          limits:
+            memory: "1.5Gi"
+            cpu: "1500m"
+      volumes:
+      - name: gitea-data
+        persistentVolumeClaim:
+          claimName: gitea-pvc
+---
+apiVersion: v1
+kind: PersistentVolumeClaim
+metadata:
+  name: gitea-pvc
+  namespace: gitea
+spec:
+  accessModes:
+  - ReadWriteOnce
+  resources:
+    requests:
+      storage: 5Gi
+---