feat(skills): add document-review skill for brainstorm/plan refinement (#112)

Add optional review and refine step to workflows:brainstorm and workflows:plan
that checks documents for clarity, completeness, user intent, and YAGNI.

- New document-review skill with review questions and evaluation criteria
- Brainstorm Phase 4 offers "Review and refine" option
- Plan post-generation offers "Review and refine" after technical review
- Includes YAGNI-based simplification guidance
- Max 2 iteration rounds before suggesting to proceed

Co-authored-by: Kieran Klaassen <kieranklaassen@users.noreply.github.com>

plugins/compound-engineering/README.md

@@ -94,7 +94,7 @@ Core workflow commands use `workflows:` prefix to avoid collisions with built-in
 | `/create-agent-skill` | Create or edit Claude Code skills |
 | `/generate_command` | Generate new slash commands |
 | `/heal-skill` | Fix skill documentation issues |
-| `/plan_review` | Multi-agent plan review in parallel |
+| `/technical_review` | Multi-agent technical/architecture review in parallel |
 | `/report-bug` | Report a bug in the plugin |
 | `/reproduce-bug` | Reproduce bugs using logs and console |
 | `/resolve_parallel` | Resolve TODO comments in parallel |
@@ -129,7 +129,8 @@ Core workflow commands use `workflows:` prefix to avoid collisions with built-in
 
 | Skill | Description |
 |-------|-------------|
-| `brainstorming` | Guided ideation for exploring requirements and approaches |
+| `brainstorming` | Explore requirements and approaches through collaborative dialogue |
+| `document-review` | Improve documents through structured self-review |
 | `every-style-editor` | Review copy for Every's style guide compliance |
 | `file-todos` | File-based todo tracking system |
 | `git-worktree` | Manage Git worktrees for parallel development |