feat: v3.0.0 architecture overhaul

- Rename marketplace to lm-claude-plugins
- Move MCP servers to root with symlinks
- Add 6 PR tools to Gitea MCP (list_pull_requests, get_pull_request,
  get_pr_diff, get_pr_comments, create_pr_review, add_pr_comment)
- Add clarity-assist plugin (prompt optimization with ND accommodations)
- Add git-flow plugin (workflow automation)
- Add pr-review plugin (multi-agent review with confidence scoring)
- Centralize configuration docs
- Update all documentation for v3.0.0

BREAKING CHANGE: MCP server paths changed, marketplace renamed

Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>

plugins/pr-review/commands/pr-summary.md

@@ -0,0 +1,103 @@
+# /pr-summary - Quick PR Summary
+
+## Purpose
+
+Generate a quick summary of PR changes without conducting a full multi-agent review.
+
+## Usage
+
+```
+/pr-summary <pr-number> [--repo owner/repo]
+```
+
+## Behavior
+
+### Step 1: Fetch PR Data
+
+Using Gitea MCP tools:
+1. `get_pull_request` - PR metadata
+2. `get_pr_diff` - Code changes
+
+### Step 2: Analyze Changes
+
+Quick analysis of:
+- Files modified
+- Types of changes (features, fixes, refactoring)
+- Scope and impact
+
+### Step 3: Generate Summary
+
+```
+═══════════════════════════════════════════════════
+PR Summary: #123 - Add user authentication
+═══════════════════════════════════════════════════
+
+Author: @johndoe
+Branch: feat/user-auth → development
+Status: Open (ready for review)
+
+───────────────────────────────────────────────────
+CHANGES OVERVIEW
+───────────────────────────────────────────────────
+
+Files: 12 changed
+  + 8 new files
+  ~ 3 modified files
+  - 1 deleted file
+
+Lines: +234 / -45 (net +189)
+
+───────────────────────────────────────────────────
+WHAT THIS PR DOES
+───────────────────────────────────────────────────
+
+This PR adds user authentication functionality:
+
+1. **New API endpoints**
+   - POST /api/auth/login
+   - POST /api/auth/register
+   - POST /api/auth/logout
+
+2. **Frontend components**
+   - LoginForm component
+   - RegisterForm component
+   - Auth context provider
+
+3. **Database changes**
+   - New users table
+   - Sessions table
+
+───────────────────────────────────────────────────
+KEY FILES
+───────────────────────────────────────────────────
+
+• src/api/auth/login.ts (+85) - Login endpoint
+• src/api/auth/register.ts (+120) - Registration
+• src/components/LoginForm.tsx (+65) - Login UI
+• src/db/migrations/001_users.sql (+45) - Schema
+
+───────────────────────────────────────────────────
+QUICK ASSESSMENT
+───────────────────────────────────────────────────
+
+Scope: Medium (authentication feature)
+Risk: Medium (new security-sensitive code)
+Recommendation: Full /pr-review suggested
+
+═══════════════════════════════════════════════════
+```
+
+## Output
+
+Summary report with:
+- PR metadata
+- Change statistics
+- Plain-language description of changes
+- Key files list
+- Quick risk assessment
+
+## When to Use
+
+- Get quick overview before full review
+- Triage multiple PRs
+- Understand PR scope