ci: retry npm ci once on the runner's intermittent SIGSEGV

The frontend deps step occasionally crashes with "Segmentation fault (core
dumped)" (exit 139) during `npm ci` — a memory/native flake on the act_runner,
unrelated to the change under test (it failed the deploy-fix PR whose only change
is the Dockerfile). Retry once with a clean node_modules before failing.

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>

.gitea/workflows/ci-deploy.yml

@@ -39,7 +39,12 @@ jobs:
         run: |
           node -v
           npm -v
-          npm ci --no-audit --no-fund
+          # npm ci occasionally segfaults on the runner (SIGSEGV/139, a memory/native
+          # flake). Retry once with a clean node_modules before failing the job.
+          npm ci --no-audit --no-fund \
+            || ( echo "npm ci failed ($?) — cleaning node_modules and retrying once..." \
+                 && rm -rf node_modules \
+                 && npm ci --no-audit --no-fund )
 
       - name: Test frontend
         working-directory: job-tracker-ui