ci: auto-update image tag in kustomization for ArgoCD sync

Add Drone CI step to update kustomization.yaml newTag with commit SHA
after image build, enabling ArgoCD to detect manifest changes and
auto-deploy new images.

.drone.yml

@@ -22,3 +22,19 @@ steps:
         --destination=192.168.68.11:30500/invest-api:latest
         --insecure
         --skip-tls-verify
+
+  - name: update-manifests
+    image: alpine/git:latest
+    environment:
+      GITEA_TOKEN:
+        from_secret: gitea_token
+    commands:
+      - cd /drone/src
+      - TAG=$(echo $DRONE_COMMIT_SHA | cut -c1-8)
+      - sed -i "s/newTag:.*/newTag: $TAG/" k8s/base/kustomization.yaml
+      - git config user.email "drone@colacoder.com"
+      - git config user.name "Drone CI"
+      - git add k8s/base/kustomization.yaml
+      - "git commit -m \"chore: update image tag to $TAG [skip ci]\""
+      - git remote set-url origin https://kai:$GITEA_TOKEN@git.colacoder.com/kai/openbb-invest-api.git
+      - git push origin main

k8s/base/kustomization.yaml

@@ -9,3 +9,7 @@ resources:
   - deployment.yaml
   - service.yaml
   - ingress.yaml
+
+images:
+  - name: 192.168.68.11:30500/invest-api
+    newTag: latest