WP-0001 complete: v1.1.0 lazy registry and install performance

Lazy-load agent registry (frontmatter index, parse on demand), copy
agents by path during install, fix Makefile template tab lint issue,
add registry performance tests, bump to 1.1.0, document CLI reinstall
after pull.

CONTRIBUTING.md

@@ -24,6 +24,14 @@ This document outlines how to get started, how we organise work, and how to help
 4. Verify setup: `make test-quick` or `pytest tests/`
 5. Familiarize yourself with agent system (see CLAUDE.md)
 
+**After pulling updates:** reinstall the CLI so new commands are available:
+
+```bash
+pip install -e .              # project venv
+# or
+pipx install -e . --force     # global pipx install
+```
+
 ## Development Workflow
 
 ### Project Structure