feat(marketplace): command consolidation + 8 new plugins (v8.1.0 → v9.0.0) [BREAKING]

Phase 1b: Rename all ~94 commands across 12 plugins to /<noun> <action>
sub-command pattern. Git-flow consolidated from 8→5 commands (commit
variants absorbed into --push/--merge/--sync flags). Dispatch files,
name: frontmatter, and cross-reference updates for all plugins.

Phase 2: Design documents for 8 new plugins in docs/designs/.

Phase 3: Scaffold 8 new plugins — saas-api-platform, saas-db-migrate,
saas-react-platform, saas-test-pilot, data-seed, ops-release-manager,
ops-deploy-pipeline, debug-mcp. Each with plugin.json, commands, agents,
skills, README, and claude-md-integration. Marketplace grows from 12→20.

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

plugins/ops-release-manager/skills/changelog-conventions.md

@@ -0,0 +1,74 @@
+---
+description: Keep a Changelog format, Unreleased section management, and category ordering
+---
+
+# Changelog Conventions Skill
+
+## Overview
+
+Standards for maintaining a changelog following the Keep a Changelog format (keepachangelog.com). The changelog is the primary release communication artifact.
+
+## File Structure
+
+```markdown
+# Changelog
+
+All notable changes to this project will be documented in this file.
+
+The format is based on [Keep a Changelog](https://keepachangelog.com),
+and this project adheres to [Semantic Versioning](https://semver.org).
+
+## [Unreleased]
+
+### Added
+- New features go here during development
+
+## [2.3.1] - 2026-01-15
+
+### Fixed
+- Bug fix description
+
+## [2.3.0] - 2026-01-01
+
+### Added
+- Feature description
+
+[Unreleased]: https://github.com/user/repo/compare/v2.3.1...HEAD
+[2.3.1]: https://github.com/user/repo/compare/v2.3.0...v2.3.1
+[2.3.0]: https://github.com/user/repo/releases/tag/v2.3.0
+```
+
+## Category Ordering
+
+Categories must appear in this order (only include categories with entries):
+
+1. **Added** — New features
+2. **Changed** — Changes to existing functionality
+3. **Deprecated** — Features that will be removed in future
+4. **Removed** — Features removed in this release
+5. **Fixed** — Bug fixes
+6. **Security** — Security vulnerability fixes
+
+## Unreleased Section Management
+
+### During Development
+All changes go under `[Unreleased]`. Never create a versioned section until release time.
+
+### At Release Time
+1. Replace `[Unreleased]` heading with `[X.Y.Z] - YYYY-MM-DD`
+2. Add new empty `[Unreleased]` section above
+3. Update comparison links at bottom of file
+
+### Entry Writing Guidelines
+- Start with a verb (Add, Fix, Change, Remove, Deprecate)
+- Focus on user impact, not implementation details
+- Reference issue numbers where applicable
+- Keep entries concise (one line preferred)
+- Group related changes into a single entry when appropriate
+
+## Comparison Links
+
+Maintain comparison links at the bottom of the file:
+- `[Unreleased]` compares latest tag to HEAD
+- Each version compares to the previous version
+- First version links to the release tag