Highlight Operator title for pending approvals

[edwin-zvs]

Summary

• Track pending tool approvals per session so the Operator title can surface orchestrator approval state.
• Render operator ! in warning/bold style when the Operator has a pending approval.
• Highlight the Operator title on hover.
• Clicking the Operator title toggles the Operator/minibuffer panel open or closed.

Tests

• cargo test -p agentd-cli operator_title_marks_pending_approval_and_toggles_panel_on_click
• cargo test -p agentd-cli operator_matrix_widgets_render_without_unbounded_padding
• cargo build
• git diff --check