Fix Windows release retry and generated notes

[igorcosta]

What changed

• Creates the versioned GitHub Release in setup, before platform builds begin.
• Uploads the web bundle and every successful platform's verified assets directly to that existing Release.
• Leaves finalization to merge and upload the installer manifest and checksums.
• Fixes the Windows Git Bash temporary-path failure, uses actions/setup-node@v7, supports immutable-tag retries from the default branch, and generates commit-derived notes.

Why

macOS and Windows installers must appear on the GitHub Release as soon as their own verified jobs finish, instead of waiting for every platform. This matches the Buzz release lifecycle.

Validation

• bun run check:release
• actionlint -config-file .github/actionlint.yaml
• git diff --check