Fix push notifications and hide action button on completed tasks

- Add push_certs directory to Dockerfile for APNs support
- Fix notification_id conversion using strconv.FormatUint instead of string(rune())
- Remove "view" from completed tasks button_types so action button is hidden

🤖 Generated with [Claude Code](https://claude.com/claude-code)

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

Dockerfile

@@ -126,6 +126,9 @@ COPY --from=builder /app/static /app/static
 COPY --from=builder /app/migrations /app/migrations
 COPY --from=builder /app/seeds /app/seeds
 
+# Copy push notification certificates
+COPY --from=builder /app/push_certs /app/push_certs
+
 # Copy admin panel standalone build (Next.js recommended layout)
 COPY --from=admin-builder /app/.next/standalone/ /app/
 COPY --from=admin-builder /app/public /app/public