- Runner label: self-hosted -> ubuntu-latest (act registers as ubuntu-latest, not self-hosted) - Flutter SDK: 3.44.8 (nonexistent) -> 3.35.3 (latest stable) - SDK platform: macOS -> Linux (act runs Linux containers) - JDK: macOS ARM64 -> Linux x86_64 - Android cmdline tools: macOS -> Linux - iOS build: skip gracefully (requires macOS host with Xcode)