Send now: deliver a queued message right away

What

While Claude is working, a message you type waits in a queue until the current turn finishes. This release adds the pieces of a "send now" action that stops the current turn so the waiting message goes through straight away:

• chat:sendNow: a new keyboard action bound to ctrl+x ctrl+s and ctrl+enter.
• sendNow: each kind of connection now states whether it supports this. It is true for ccr and false for ssh and direct, and false by default. The message box checks caps.sendNow together with the key binding.
• A thin-client request (used by a lightweight app connected to a session), an interrupt with send_now: true, answers stopped, delivering or nothing_waiting, or failed if something goes wrong.
• The message submit handler can now pass a sendNow option, and the footer gained a footerNavActive input.
• The hint for editing a queued shell command now reads "clear input to edit shell command".
• In the same area, a new branch shows a component tied to a task.

Why

Where it is offered, you can cut a long turn short to get a new message in, instead of waiting for Claude to finish. Connections marked as not supporting it keep the old wait-in-queue behaviour.