Added mandatory validation steps to release workflow:
- Job 1: validate (hassfest + HACS) - runs before release
- Job 2: lint (Ruff check + format) - runs before release
- Job 3: sync-manifest - only runs if validation passes
- Job 4: release-notes - only runs if all previous jobs pass
This ensures no release is created if code doesn't pass validation.
Fixed generate-release-notes script to suppress colored output in CI:
- Added log_info() wrapper that sends output to stderr in CI
- Keeps release notes clean (only markdown, no ANSI codes)
- Local execution still shows colored output for better UX
Impact: Release workflow now fails fast if validation fails. Release
notes are clean without shell output artifacts.