[FEATURE] Add an in-session command to jump straight to Agent View (like /workflows and /tasks)

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

/workflows and /tasks both open an immediate, live-updating view of in-flight work the moment you invoke them, from anywhere in an active session. Agent View has no equivalent in-session entry point.

Today the only way to reach Agent View from inside a running session is the left-arrow key, and that path has real friction:

• It only detaches/navigates when the message input box is empty — if anything is typed, the same key just moves the text cursor instead (reported in #77286: "←-to-detach is undiscoverable, mode-dependent (empty input only)"). So in practice you have to first clear or never type into the input, then press ←.
• There's no on-screen hint that ← does this, and no indication of which "mode" the key is currently in (navigate vs. edit text).
• A separate issue (#73970) reports the ← hint displaying even outside an agent-view-managed session, adding to the confusion about when the key actually works.

So the single most common thing to want mid-session — "what are my agents doing right now, does anything need me" — requires an undiscoverable, state-dependent key rather than a direct command, unlike workflows and tasks.

Note: Agent View itself already groups sessions into Ready for review / Needs input / Working / Completed (since v2.1.203) with live status — that part of the experience already matches /workflows//tasks. The gap is purely the entry point.

Proposed Solution

Add a slash command, invocable from anywhere in an active session, that immediately backgrounds the current session (if one is in the foreground) and opens Agent View — the same interaction model /workflows and /tasks already use.

On naming: the obvious candidate is /agents, but that name was previously used for a different feature — an interactive wizard for creating/editing custom subagent definitions, removed in v2.1.198 and separately requested back in #72962. Reusing /agents for this would either resurrect confusion with that removed wizard or require deciding the wizard is permanently retired. A distinct name (e.g. /agent-view or /fleet, matching the internal "FleetView" terminology already used for this screen) would avoid that ambiguity — but if the wizard is not coming back, reusing /agents is also reasonable. Deferring to maintainers on naming; the entry-point gap is the actual ask.

No new grouping/status logic is needed — Agent View's existing Needs input/Working/Completed/Ready for review sections already cover that.

Alternative Solutions

Current workaround: make sure the input box is empty, then press ←. This works but is exactly the friction described in #77286 — it's silent about whether it will work in the input's current state, and typing anything first (e.g. mid-draft of the next prompt) blocks it until the input is cleared.

Priority

Medium - Would be very helpful

Feature Category

Interactive mode (TUI)

Use Case Example

1. I'm mid-session with several background agents running (spawned via the Agent tool, or a workflow's fan-out).
2. I want to quickly check whether any of them are blocked waiting on me, without losing whatever I've already typed into the input box.
3. With this feature, I'd type /agent-view (or whatever it ends up named) and land directly on the Needs input/Working/Completed board — the same motion as /workflows or /tasks today.
4. Right now I instead have to notice/clear the input box and press ←, hoping it's actually in "navigate" mode.

Additional Context

• Related, not duplicate: #77286 (documents the ←-to-detach discoverability/mode problem this request routes around), #73970 (← hint shown outside agent-view-managed sessions), #72962 (separate ask to restore the old /agents subagent-creation wizard — different feature, flagged here only because of the naming overlap).
• /workflows and /tasks are the existing precedent for "slash command opens a live status view immediately" — this request asks for the same pattern to cover Agent View.