0.10.2: no images behind mosh; tmux by TERM

Images are off behind mosh, so emoji stay visible. Mosh syncs only text and drops every image escape, which left blank cells where emoji should be. behindMosh() detects mosh by walking /proc up from the app and, under tmux, up from every attached client. When it finds mosh, image mode turns off even if it was requested. HQTUI_MOSH=0|1 overrides the check. For images on a remote box, use plain SSH or WezTerm's multiplexer (wezterm connect).

tmux is recognised by TERM (tmux*, screen*) when the TMUX variable was lost, for example across su, sudo or some SSH hops. New: inTmux(). PR #123.