[maotora]

Summary

This PR finishes the packaging and distribution phase for brave-updater.

• adds release-to-repo dispatch support in the main release workflow
• documents the cross-repo packaging sync model
• wires the main repo to notify the Homebrew tap and Scoop bucket after tagged releases
• keeps scheduled fallback syncs in the external repos for safety

External repos created

• HackEAC/homebrew-brave-updater
• HackEAC/scoop-bucket

Both external repos now include:

• MIT license
• user-facing README
• sync workflow that pulls rendered release assets from HackEAC/braver-tz
• validation workflow for their package format

Verification

• python3 -m unittest discover -v
• all 63 tests passing locally
• workflow YAML parsed locally for all three repos
• PACKAGING_SYNC_TOKEN configured in HackEAC/braver-tz
• manual repository_dispatch checks completed successfully for both external repos

Notes

• PyPI publication still depends on the pending PyPI org and project approval
• until PyPI is approved, tagged releases should still generate GitHub release assets and update the Homebrew and Scoop repos once the release workflow runs