Restore 'start a dev server, use it in a later call' as an explicit opt-in
after #816 made bash reap its whole process group on return. The surface
mirrors the dominant coding-agent convention: bash(run_in_background=true)
returns a bash_N handle immediately; bash_output(id, filter?) returns only
output produced since the previous read plus status and exit code;
kill_shell(id) terminates the shell's whole process group.
- Per-session BackgroundShellRegistry: capped rolling line buffer with
drop-oldest gap accounting, exit-order record pruning, owner scoping for
task_agents (shells reaped when the agent finishes), liveness-guarded
group kills (a stale pgid is never signalled), budgeted teardown joins.
- Exit notices ride a shared external-event rail (sanitize, soft cap,
channel 'any', idle wake) now common to watch fires; a new 'quiet'
NudgeQueue channel lets a user cancel defer pending notices without
letting them re-wake the stopped workstream, and failed wake delivery
re-queues external notices seq- and predicate-intact without re-arming
the wake gate.
- The bash_output filter runs in a killable subprocess: sre holds the GIL
for an entire search, so no in-process timeout can bound a hostile
pattern. Scrubbed child env, pinned UTF-8 pipes, honest timeout-vs-
helper-failure error taxonomy, per-line match window with explicit
clipping notes; a failed filter never consumes the delta.
- run_in_background rides the bash intent-judge projection; bash_output is
exempt from the repeat warning but still recorded so interleaved polls
keep breaking other tools' streaks; all bash boolean args share one
lenient coercion dialect.
- Shells survive generation cancel and die with the workstream: every
teardown path funnels through ChatSession.close(); CLI exit and the
server lifespan now close every loaded session, signal-first and
Ctrl-C-safe, so nothing detached outlives a graceful shutdown.
Patrick Buckley