ci: retry frontend build once on silent failure

npm run build (Terser minify + fork-ts-checker workers) has now died three
distinct ways on this runner in this session: a printed Terser minify error,
an explicit SIGSEGV, and a fully silent kill with zero output between
'Creating an optimized production build...' and the failure line (OOM/SIGSEGV
signature — process killed before it could flush an error). All three are the
same resource-starved-runner class as the npm ci and dotnet-install flakes
already retried elsewhere in this workflow. Retry once, matching that pattern.

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

.gitea/workflows/ci-deploy.yml

@@ -70,7 +70,12 @@ jobs:
           CI: 'false'
           GENERATE_SOURCEMAP: 'false'
           NODE_OPTIONS: --max-old-space-size=4096
-        run: npm run build
+        # CRA's build (Terser minify + fork-ts-checker workers) has repeatedly died silently on
+        # this runner with no error output (OOM/SIGSEGV signature — same resource-starved-runner
+        # class as the npm ci and dotnet-install flakes elsewhere in this workflow). Retry once.
+        run: |
+          npm run build \
+            || ( echo "Frontend build failed ($?) — retrying once..." && npm run build )
 
   deploy:
     needs: test