[S.5] Create GitHub release workflow

[LennyObez]

Release: 1.0.0 | Area: CI/Release | Type: Feature | Priority: P2 | Risk: Medium | Effort: M | Stability: Stable
Dependencies: 2.1, 2.7

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No release automation exists. Create a GitHub Actions workflow for automated releases.

Workflow steps:

1. Trigger on tag push (e.g., v1.0.0)
2. Run full QA suite (composer qa, pnpm lint, pnpm test)
3. Create GitHub Release with changelog
4. Trigger Packagist webhook for Composer package update
5. Post release notification (optional)

Tasks:

• Create .github/workflows/release.yml
• Configure Packagist webhook
• Add changelog generation (from conventional commits)
• Test with a pre-release tag

Acceptance criteria:

• Tag push triggers automated release
• QA gates must pass before release is created
• GitHub Release includes changelog
• Packagist is updated automatically