fix(frontend): keep the config template outside the web root so a restart can't crash-loop

.gitattributes

@@ -7,3 +7,6 @@
 # Dockerfiles
 Dockerfile text eol=lf
 *.dockerfile text eol=lf
+
+# Front-end image files are copied verbatim into a Linux image and served from it
+clients/*/docker/** text eol=lf

.github/workflows/frontend.yml

@@ -111,10 +111,58 @@ jobs:
           path: clients/${{ matrix.app }}/playwright-report
           retention-days: 7
 
+  # The nginx image renders /config.json at every start. Restarting the same container
+  # has to bring it back: the entrypoint once deleted its own template after the first
+  # render, so any restart crash-looped, and nothing else here builds or runs the image.
+  container:
+    name: Container (${{ matrix.app }})
+    needs: changes
+    if: needs.changes.outputs.frontend == 'true'
+    runs-on: ubuntu-latest
+    strategy:
+      fail-fast: false
+      matrix:
+        app: [admin, dashboard]
+    steps:
+      - name: Checkout
+        uses: actions/checkout@v6
+
+      - name: Build image
+        run: docker build -t fsh-${{ matrix.app }}:ci clients/${{ matrix.app }}
+
+      - name: Smoke test start and restart
+        env:
+          IMAGE: fsh-${{ matrix.app }}:ci
+        run: |
+          set -euo pipefail
+          docker run -d --name smoke -p 8080:80 \
+            -e FSH_API_URL=http://api.example.test -e FSH_DEFAULT_TENANT=acme \
+            -e FSH_DASHBOARD_URL=http://app.example.test "$IMAGE"
+          check() {
+            rm -f config.json
+            for _ in $(seq 1 20); do
+              curl -fsS http://localhost:8080/config.json -o config.json && break
+              sleep 1
+            done
+            [ "$(docker inspect -f '{{.State.Running}} {{.RestartCount}}' smoke)" = "true 0" ]
+            jq -e '.apiBase == "http://api.example.test" and .defaultTenant == "acme"' config.json
+          }
+          check
+          if curl -fsS http://localhost:8080/config.json.template | grep -qF '${FSH_API_URL}'; then
+            echo "::error::config.json.template is served from the web root"
+            exit 1
+          fi
+          docker restart smoke
+          check
+
+      - name: Container logs
+        if: failure()
+        run: docker logs smoke
+
   # Single required status check — see backend.yml for the rationale.
   frontend-ci:
     name: Frontend CI
-    needs: [changes, lint-build, e2e]
+    needs: [changes, lint-build, e2e, container]
     if: always()
     runs-on: ubuntu-latest
     steps:

clients/admin/Dockerfile

@@ -23,9 +23,10 @@ RUN apk add --no-cache gettext
 RUN rm -rf ./* /etc/nginx/conf.d/default.conf
 COPY docker/nginx.conf /etc/nginx/conf.d/default.conf
 
-# Copy the built bundle, the runtime config template, and the entrypoint
+# Copy the built bundle, the runtime config template (outside the web root so
+# it is never served), and the entrypoint
 COPY --from=build /app/dist/ ./
-COPY docker/config.json.template ./config.json.template
+COPY docker/config.json.template /etc/fsh/config.json.template
 COPY docker/docker-entrypoint.sh /docker-entrypoint.sh
 RUN chmod +x /docker-entrypoint.sh
 

clients/admin/docker/docker-entrypoint.sh

@@ -10,10 +10,8 @@ set -e
 
 export FSH_API_URL FSH_DASHBOARD_URL FSH_DEFAULT_TENANT
 
-# Render the runtime config from the template, writing into nginx's web root.
-envsubst < /usr/share/nginx/html/config.json.template > /usr/share/nginx/html/config.json
-
-# Drop the template so it isn't served accidentally.
-rm /usr/share/nginx/html/config.json.template
+# Render the runtime config into nginx's web root on every start. The template
+# lives outside the web root, so it is never served and survives a restart.
+envsubst < /etc/fsh/config.json.template > /usr/share/nginx/html/config.json
 
 exec nginx -g 'daemon off;'

clients/dashboard/Dockerfile

@@ -13,7 +13,7 @@ RUN apk add --no-cache gettext
 RUN rm -rf ./* /etc/nginx/conf.d/default.conf
 COPY docker/nginx.conf /etc/nginx/conf.d/default.conf
 COPY --from=build /app/dist/ ./
-COPY docker/config.json.template ./config.json.template
+COPY docker/config.json.template /etc/fsh/config.json.template
 COPY docker/docker-entrypoint.sh /docker-entrypoint.sh
 RUN chmod +x /docker-entrypoint.sh
 EXPOSE 80

clients/dashboard/docker/docker-entrypoint.sh

@@ -6,8 +6,7 @@ set -e
 
 export FSH_API_URL FSH_DEFAULT_TENANT
 
-envsubst < /usr/share/nginx/html/config.json.template \
+envsubst < /etc/fsh/config.json.template \
        > /usr/share/nginx/html/config.json
-rm /usr/share/nginx/html/config.json.template
 
 exec nginx -g 'daemon off;'