[FEATURE] Desktop: grid overview of all active sessions, ordered by "needs my action" priority, as an alternative to the sidebar list

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

When I run many sessions across many projects in Claude Code Desktop, the left sidebar becomes the bottleneck. With a long list grouped by project I have to scroll and scan to find which session is blocked on me (permission prompt, question, plan approval), which has finished, and which is still working. Sessions that need my action are scattered across project groups and can sit unnoticed while others idle. Switching between them is slow because the sidebar is a narrow one-dimensional list that gives no at-a-glance picture of overall state.

The cost is that parallel agents are only as fast as my reaction time to their blocking states. Anything that makes me hunt for the session that needs me directly reduces the value of running sessions in parallel.

Proposed Solution

Add a "Sessions overview" view in Desktop (toggle next to the sidebar, or a keyboard shortcut) that shows every active session as a card in a grid, sorted by how urgently it needs me.

Card contents: project name, session title, a one-line status or last message, elapsed time in the current state, and a state badge. Clicking a card (or pressing 1-9 / arrow keys + Enter) jumps straight into that session. Optionally allow a quick inline reply for simple prompts (approve/deny a permission, answer a short question) without leaving the grid.

Default ordering by action needed, highest first:

1. Blocked on me: permission request, question for the user, plan awaiting approval
2. Errored or stopped unexpectedly
3. Finished and unreviewed (waiting for me)
4. Running (working, no action needed)
5. Idle / archived

Within a tier, order by longest waiting first. Allow manual pinning and a filter by project or state. Keep the sidebar as it is for people who prefer it; this is an additional view, not a replacement. The grid should scale from a handful of sessions to dozens (compact card density option, scrollable, or grouped by tier with collapsible sections).

Alternative Solutions

Current workaround is scrolling the sidebar, collapsing project groups, and watching for the attention dots. This breaks down past roughly 10 sessions across several projects, and collapsed groups hide sessions that are waiting on me.

Related requests solve parts of this but not the whole: a sidebar section for running sessions (#98957), a "finished, waiting for you" dot (#100335), filtering to attention dots (#99571), and showing finished sessions on the home screen (#100393). A grid with a built-in action-needed ordering would cover these in one place rather than adding more sidebar sections and filters.

Priority

High - Significant impact on productivity

Feature Category

Other

Use Case Example

1. I have around 15 sessions open across 6 projects, several running in parallel.
2. Three of them are waiting on me (two permission prompts, one plan approval), but they sit in different collapsed project groups in the sidebar.
3. With this feature I open the overview, see those three at the top of the grid, and handle them in a few seconds, then see which finished sessions need review.
4. This saves the time spent scrolling and expanding groups, and shortens how long agents sit blocked.

Additional Context

Possibly related (partial overlap, none propose a grid or priority ordering): #71783 (session sidebar structure), #98957, #100335, #99571, #100393. The VS Code extension already has a multi-session grid (see #100442), so this would bring a similar concept to Desktop with action-needed ordering added.

Rough layout idea: a responsive card grid, state-coloured badges, tiers as collapsible sections, and a persistent shortcut to toggle between overview and the active session.