chore: scaffold crewai-cli package and update workspace config

Add the new lib/cli package skeleton with pyproject.toml, README,
and __init__.py. Register it as a uv workspace member and update
root linting, mypy, bandit, and pytest config to include the new
package paths.

lib/cli/README.md

@@ -0,0 +1,15 @@
+# crewai-cli
+
+CLI for CrewAI - scaffold, run, deploy and manage AI agent crews without installing the full framework.
+
+## Installation
+
+```bash
+pip install crewai-cli
+```
+
+Or install alongside the full framework:
+
+```bash
+pip install crewai[cli]
+```