fix: preserve directory structure for feature overlay kustomize build

Kustomize rejects absolute paths for resource references. Instead of
rewriting ../../base to an absolute path, copy both base and overlay
into a temp directory preserving the relative path structure.

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

.gitea/workflows/ci.yml

@@ -311,10 +311,12 @@ jobs:
           done
       - name: Substitute placeholders and deploy
         run: |
-          # Work on a copy so we don't modify the repo
-          cp -r deploy/overlays/feature /tmp/feature-overlay
+          # Work on a copy preserving the directory structure so ../../base resolves
+          mkdir -p /tmp/feature-deploy/deploy/overlays
+          cp -r deploy/base /tmp/feature-deploy/deploy/base
+          cp -r deploy/overlays/feature /tmp/feature-deploy/deploy/overlays/feature
           # Substitute all BRANCH_* placeholders
-          for f in /tmp/feature-overlay/*.yaml; do
+          for f in /tmp/feature-deploy/deploy/overlays/feature/*.yaml; do
             sed -i \
               -e "s|BRANCH_NAMESPACE|${BRANCH_NS}|g" \
               -e "s|BRANCH_SCHEMA|${BRANCH_SCHEMA}|g" \
@@ -322,9 +324,7 @@ jobs:
               -e "s|BRANCH_SHA|${{ github.sha }}|g" \
               "$f"
           done
-          # Fix kustomization base path (since we moved the overlay)
-          sed -i 's|../../base|'"$(pwd)"'/deploy/base|g' /tmp/feature-overlay/kustomization.yaml
-          kubectl apply -k /tmp/feature-overlay
+          kubectl apply -k /tmp/feature-deploy/deploy/overlays/feature
       - name: Wait for init-job
         run: |
           kubectl -n "$BRANCH_NS" wait --for=condition=complete job/init-schema --timeout=60s || \