Summary

Declutter the Control UI sidebar: a small customizable pinned nav set, a collapsed "More" section for the rest, Settings in the footer, and the collapse toggle moved to the topbar.

Problem to solve

The sidebar shows three always-expanded nav groups (Control, Agent, Settings) with 13 entries plus the session list, brand header with its own collapse button, and footer utilities. When the main job is talking to the agent, the chrome competes with the conversation, and there is no way to choose which destinations stay visible.

Proposed solution

Restructure the sidebar around a small user-customizable pinned set (similar to the Codex desktop app):

• Sessions stay on top (New session, Recent, All sessions).
• A few pinned nav items follow (default: Overview, Workboard, Agents).
• Every other destination moves into a collapsed More section.
• Right-clicking the nav (or the "Customize sidebar" entry under More) opens a menu with per-destination pin checkmarks and a reset action; the selection persists in the browser-local Control UI settings alongside the existing nav preferences.
• Settings moves to the sidebar footer next to Docs.
• The sidebar collapse toggle moves out of the brand header into the topbar as a small icon button next to the terminal toggle.

Alternatives considered

Keeping the fixed three-group layout and only persisting per-group collapse — already exists, but does not reduce the default visual load and offers no per-item control.

Impact

Affected: every Control UI user, on every page.
Severity: medium (usability/focus).
Frequency: always.
Consequence: visual noise and harder orientation next to the chat surface.

Evidence/examples

Before/after screenshots in the linked PR.