Prevent recovery from writing into active remote panes (#76)

* Prevent streamer recovery from writing remote input

* fix: don't let a leftover spawn claim freeze later heals

Clear the pending file when retype gives up, and treat claims older
than 30s as abandoned so session-restore can type again. Also share
one state_dir in the pane startup path.

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Co-authored-by: niko <nikokristanto24@gmail.com>