Closed local terminals leave zombie shells, and two Tauri plugins are registered for nothing #153

Tested against main (894ea12).

Closed local terminals leave their shell behind

LocalTerminals::remove and clear (desktop/src-tauri/src/state.rs:309-327) drop the LocalTerminal, and with it the portable-pty child. In portable-pty 0.9 that is a plain std::process::Child, which neither kills nor waits when dropped. Dropping the PTY master hangs up the tty, so a typical shell exits. Nothing ever collects its exit status, though, so every closed local tab leaves a zombie process until the app quits. A shell that ignores SIGHUP keeps running.

The unit tests in state.rs call child.kill() by hand after every remove, which is the step production code never takes.

Two plugins nothing uses

tauri-plugin-os and tauri-plugin-process are registered in main.rs:124-125, and os:default is granted in capabilities/default.json. No frontend code imports @tauri-apps/plugin-os or @tauri-apps/plugin-process, or invokes plugin:os|… / plugin:process|…. Restarts go through AppHandle::request_restart. The two plugins only add code to the binary, and they let the page read hostname, locale and OS version for nothing. #123 drops the os:default grant; this removes the plugins themselves.

Also noticed, not changed here

SftpManager::read_file, write_file and stat have no callers. read_file loads a whole remote file into memory. They sit in code #140 rewrites, so removing them belongs after that lands.