The pipeline was failing because Lint and Test jobs used runs-on:
ubuntu-latest which 'act' does not recognize as a local runner label.
On the Mac build server (Magrathea), these jobs were routed to the
macOS runner where Docker containers failed to run Flutter correctly.
Changed:
- lint: ubuntu-latest -> [self-hosted, linux]
- test: ubuntu-latest -> [self-hosted, linux]
- build-android: ubuntu-latest (unchanged)
- build-ios: [self-hosted, macos] (unchanged)
The Linux runner should pick up lint/test while Magrathea handles iOS
builds as intended.