Fix CI: scope NODE_ENV=production to the build step only

Setting it job-wide made `npm ci` treat NODE_ENV=production as an
implicit --omit=dev, silently skipping eslint/typescript/test
devDependencies and failing Lint with "eslint: not found".

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

.gitea/workflows/ci.yml

@@ -14,8 +14,11 @@ jobs:
     # app is force-dynamic, so `next build` never touches Postgres. These
     # are dummy values only so a real config error (a missing secret) is
     # never silently masked by CI happening to run without one.
+    #
+    # NODE_ENV is deliberately NOT set here: `npm ci` treats a production
+    # NODE_ENV as `--omit=dev`, which would skip eslint/typescript/etc. and
+    # break Lint/Typecheck/Test. It's set below, scoped to the Build step.
     env:
-      NODE_ENV: production
       NEXT_TELEMETRY_DISABLED: "1"
       DATABASE_URI: postgresql://ci:ci@localhost:5432/ci
       PAYLOAD_SECRET: ci-only-not-a-real-secret
@@ -42,4 +45,6 @@ jobs:
         run: npm test
 
       - name: Build
+        env:
+          NODE_ENV: production
         run: npm run build