cmux-next: restore terminal reaping with scoped startup help
The launcher probes root --help for the terminal reap option. The CLI now puts startup flags under cmux help start, so the app omitted its configured grace and closed terminal hosts kept running. The launcher retains the legacy probe and falls back to scoped startup help, preserving clients that do not support reaping.
Commit 72f0232edaf adds executable regressions first. Both the fleet and hosted Swift CI reproduce the new compact-help failure. Commit 74c4eb90006 applies the repair.
Omnibar typing and daemon state-resource tests now run in their own serial CI process. Both passed in isolated fleet filters but failed or timed out in the shared package process. Every test and existing deadline is retained. Real terminal reaping remains in the main package pass.
On 74c4eb90006, the fleet compiled the test target and passed all 15 tests across four serial filters: launcher compatibility, real terminal lifetime, omnibar typing and daemon state resources. The tagged local-backend build also succeeded. Full hosted Swift CI, Debug, Release and ci-status all pass on this exact head. The checkout network failure was recovered by retrying only Swift. This changes no UI copy or localization keys.
Driftwood g1 🪄
run: run_cx_next_newtab_3_20261005
intention: land this base repair, then #17347 with green exact-head checks