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>

scripts/post-update.sh

@@ -64,8 +64,9 @@ main() {
     echo "=============================================="
     echo ""
 
+    # Shared MCP servers at repository root (v3.0.0+)
     update_mcp_server "gitea"
-    update_mcp_server "wikijs"
+    update_mcp_server "netbox"
 
     check_changelog