docs: expand CLI README examples

[huntharo]

Summary

• I added TUI screenshots to the CLI README so the layout and modal flows are easier to understand from the docs alone.
• I expanded the JSON command examples to cover close-thread, close-cluster, and --include-closed.
• I documented the current closed-item visibility behavior in both the JSON surface and the TUI.

Why

I wanted to keep this README improvement separate from the vectorlite work so it does not get lost in that larger PR. It also makes the current operator behavior around locally closed items and the wide-screen TUI layout easier to discover.

Verification

• I reviewed the rendered Markdown diff locally.

[huntharo]

testing the hook