Propagate sigint_timeout/sigkill_timeout to the final process.stop() on exit

[cycsmail]

run_process() forwards sigint_timeout/sigkill_timeout to process.stop() on each reload, but the final stop in the finally block was called with no arguments, so on exit/Ctrl+C it fell back to the default 5s/1s timeouts and ignored the values you passed in. This forwards the kwargs to that final stop too. Added a test that spies on CombinedProcess.stop and asserts both the in-loop and final stops use the custom timeouts (fails without the change, passes with it). Left arun_process alone since #258 is about sync run_process and it doesn't expose these params. run_process/cli tests pass locally (47 passed, 1 skipped), ruff clean.

Fixes #258