[FEATURE] UI/UX: Left sidebar with Pinned, Current Works, and Recents for better session management

Preflight Checklist

• [x] I have searched existing requests and this feature hasn't been requested yet
• [x] This is a single feature request (not multiple features)

Problem Statement

Claude Code currently lists all sessions in a flat, undifferentiated way. There is no distinction between a session you're actively working in right now, one you finished yesterday, and one you've pinned for ongoing reference.
This creates cognitive overhead: as the session list grows, users must mentally track which sessions are active, which are done, and which are important. Switching between an ongoing task and a recently completed one requires scrolling through an unstructured list with no visual hierarchy.
There is also no lightweight way to "close out" a session — to signal that a piece of work is done and move it out of your active view without deleting it. This makes the workspace feel cluttered over time, especially for developers juggling multiple parallel tasks.

Proposed Solution

Introduce a three-section left sidebar that reflects how developers actually think about their work:
Pinned — Sessions the user has manually pinned for long-term or recurring reference. Stays at the top, always visible.
Current Works — Sessions that are actively in progress. A session enters this section when created and stays here until the user explicitly marks it complete. This makes it immediately obvious what's on your plate right now.
Recents — Completed or inactive sessions, ordered by last activity. When the user marks a Current Works session as done (single click / keyboard shortcut), it moves here automatically.
The "mark as complete" action should be frictionless — a checkmark button or swipe gesture directly on the session row, no confirmation dialog needed.
This mirrors mental models developers already use (GitHub Projects columns, Linear's active vs. completed issues, Notion's sidebar sections) and makes Claude Code feel like a proper workbench rather than a chat history list.

Alternative Solutions

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Priority

Medium - Would be very helpful

Feature Category

Developer tools/SDK

Use Case Example

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Additional Context

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