v0.4.12

The lease's edges: this machine's own shell, a shell nobody holds, a shell that is gone

• 释放控制权 is not offered on a shell of this machine's. The button was drawn
  for every shell the window was driving, including the ones running here — and
  on those there is nobody to hand the lease to. The release drops it and the hub
  hands it to no one, so the only thing the button did was stop the window in
  front of the shell from taking the typing of the person sitting at it. It is
  drawn for the shell this window drives on another machine, where the lease
  goes back to the machine the shell runs on and that machine can type again. The
  browser client drew it on the same wrong rule and now draws it on the same
  right one.
• A shell that has ended keeps its tab, and the tab finally knows it. The hub
  forgets a session the moment its process exits — before the exit frame and
  before the session list — so no summary ever says alive=false, and the
  desktop tab, which learned liveness from the attach summary, sat over a dead
  shell offering 结束 for a process that was gone, with no way to close the tab.
  The exit frame is the only place a tab hears it now: 已退出 arrives with its
  exit code in the tooltip, the tab dims with the exit's colour on its dot, its
  row offers 关闭 where a running shell's row offers 结束, and the band offers
  关闭标签 without repeating the sentence. Nothing is sent to a shell that has
  ended — no keystrokes, no resize: a resize answered no_session was a red toast
  raised by the act of reading a shell's last lines.
• The hub's refusals say who holds the shell, or that nobody does. A frame
  that needs the lease was answered "another client controls s1" whatever the
  state was, including a shell the same client had just let go — a sentence with
  no client to name, which sends the person reading it looking for somebody who is
  not there. The hub now tells a free lease from a lost one: the refusal is
  nobody holds s1; claim it first when there is nobody to name, and a frame from
  a client one handoff behind is told the lease has moved rather than that someone
  took it. The browser client's 结束 was the case that mattered: it claimed only
  when somebody else held the lease, so on a released shell the close was refused
  and 结束 did nothing at all. It claims in every case now, stealing only from a
  live holder.
• A shell nobody holds is marked read-only, in both clients. A free lease is
  not the same fact as a taken one, but it is the same answer at the keyboard,
  and the desktop drew nothing for it: no mark on the pane, no band, and a lease
  panel that could not be drawn at all. The pane's 只读 chip, the band
  (只读：当前无人控制, with the way in beside it) and the panel (当前无人控制这个终端,
  取得控制权后你就能继续输入。) are drawn from one answer now, on shells that have
  nobody in them as well as shells that have somebody. Rows read 无人控制 where
  they used to read 控制中 for a shell no one is driving, their holder comes from
  the tab's own lease frames rather than from a broadcast that can be a push
  behind, and the tooltip says 控制端 本窗口 for a shell this window drives instead
  of denying it. A lease the window has not heard about yet is marked with
  nothing at all: the word arrives in a role frame, and a window that read that
  silence as 只读 would flash the mark over every shell a person opens.