Rename apns-dev to push-dev and unify 1Password credentials

- Rename script from apns-dev to push-dev (handles both APNs and FCM)
- Fetch credentials from Deploy/Fizzy Production (same as Kamal)
- Use _B64 env vars to avoid escaping issues with multiline keys
- Update bin/dev flag from --apns to --push

Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>

bin/dev

@@ -2,27 +2,27 @@
 
 PORT=3006
 USE_TAILSCALE=0
-USE_APNS=0
+USE_PUSH=0
 
 for arg in "$@"; do
   case $arg in
     --tailscale) USE_TAILSCALE=1 ;;
-    --apns) USE_APNS=1 ;;
+    --push) USE_PUSH=1 ;;
   esac
 done
 
-if [ "$USE_APNS" = "1" ]; then
+if [ "$USE_PUSH" = "1" ]; then
   if [ ! -f tmp/saas.txt ]; then
-    echo "Enabling SaaS mode for APNs..."
+    echo "Enabling SaaS mode for push notifications..."
     ./bin/rails saas:enable
   fi
-  echo "Loading APNs credentials from 1Password..."
-  if ! eval "$(BUNDLE_GEMFILE=Gemfile.saas bundle exec apns-dev)"; then
-    echo "Error: failed to load APNs credentials. Are you signed into 1Password?" >&2
+  echo "Loading push credentials from 1Password..."
+  if ! eval "$(BUNDLE_GEMFILE=Gemfile.saas bundle exec push-dev)"; then
+    echo "Error: failed to load push credentials. Are you signed into 1Password?" >&2
     exit 1
   fi
-  if [ -z "$APNS_ENCRYPTION_KEY" ] || [ -z "$APNS_KEY_ID" ]; then
-    echo "Error: APNs credentials not set. Missing APNS_ENCRYPTION_KEY or APNS_KEY_ID." >&2
+  if [ -z "$APNS_ENCRYPTION_KEY_B64" ] || [ -z "$APNS_KEY_ID" ]; then
+    echo "Error: Push credentials not set. Missing APNS_ENCRYPTION_KEY_B64 or APNS_KEY_ID." >&2
     exit 1
   fi
 fi