CI: give the docker stack time to build before the health probe

The 90s health window predates the docker compose fix; a cold image
build takes several minutes on a runner, so the step always hit
timeout 124 before services could start.

Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>

Author: mvalancy

.github/workflows/ci.yml

@@ -246,8 +246,8 @@ jobs:
         run: |
           npm run docker:prod &
           sleep 30
-          echo "Waiting for services to be healthy..."
-          timeout 90 bash -c 'until curl -k https://localhost:4128/health 2>/dev/null; do sleep 2; done'
+          echo "Waiting for services to be healthy (image build can take several minutes)..."
+          timeout 600 bash -c 'until curl -k https://localhost:4128/health 2>/dev/null; do sleep 5; done'
 
       - name: Run PR critical tests
         run: npm run test:pr