Use --legacy-peer-deps so npm 10 tolerates reflexbox/react 17 conflict

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

Author: lmcmz

.github/workflows/firebase-hosting-merge.yml

@@ -21,9 +21,9 @@ jobs:
       - name: clean cache
         run: npm cache clean --force
       - name: install
-        run: npm install
+        run: npm install --legacy-peer-deps
       - name: npm install
-        run: npm install
+        run: npm install --legacy-peer-deps
       - name: build
         run: npm run build
         env: