chore: cut v5.0.0 workflows release and maintenance updates

Prepare release 5.0.0 by documenting the new Workflows foundation, bumping package metadata, refreshing release notes, and extending MAINTENANCE guidance for workflows consistency and issue-closing protocol.

Co-authored-by: Cursor <cursoragent@cursor.com>

CHANGELOG.md

@@ -7,6 +7,44 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 
 ---
 
+## [5.0.0] - 2026-02-10 - "Antigravity Workflows Foundation"
+
+> Workflows are now first-class: users can run guided, multi-skill playbooks instead of manually composing skills one by one.
+
+### Added
+
+- **New orchestration skill**: `antigravity-workflows`
+  - `skills/antigravity-workflows/SKILL.md`
+  - `skills/antigravity-workflows/resources/implementation-playbook.md`
+- **New workflow documentation**: `docs/WORKFLOWS.md`
+  - Introduces the Workflows model and differentiates it from Bundles.
+  - Provides execution playbooks with prerequisites, ordered steps, and prompt examples.
+- **New machine-readable workflow registry**: `data/workflows.json`
+  - `ship-saas-mvp`
+  - `security-audit-web-app`
+  - `build-ai-agent-system`
+  - `qa-browser-automation`
+
+### Changed
+
+- **README / Onboarding docs** updated to include Workflows discovery and usage:
+  - `README.md` (TOC + "Antigravity Workflows" section)
+  - `docs/GETTING_STARTED.md` (Bundles vs Workflows guidance)
+  - `docs/FAQ.md` (new Q&A: Bundles vs Workflows)
+- **Go browser automation alignment**:
+  - Workflow playbooks now include optional `@go-playwright` hooks for Go-based QA/E2E flows.
+- **Registry sync** after workflow skill addition:
+  - `CATALOG.md`
+  - `skills_index.json`
+  - `data/catalog.json`
+  - `data/bundles.json`
+
+### Contributors
+
+- [@sickn33](https://github.com/sickn33) - Workflows architecture, docs, and release integration
+
+---
+
 ## [4.11.0] - 2026-02-08 - "Clean Code & Registry Stability"
 
 > Quality improvements: Clean Code principles and deterministic builds.