feat(doctor): add opt-in piped stdin for streaming fix execution

apps/staged/src-tauri/src/doctor.rs

@@ -55,10 +55,17 @@ fn execute_fix_options(
     command_override: Option<String>,
     env_vars: Vec<(String, String)>,
 ) -> ExecuteFixOptions {
+    // Everything else stays at doctor's defaults: Staged's fixes are
+    // non-interactive, so nothing here feeds a prompt and the child keeps
+    // inheriting stdin rather than getting a piped one; the standard fix
+    // timeout is far above any install or login this runs. Spelled with
+    // `..Default::default()` so a new doctor option doesn't break this
+    // workspace-excluded crate, which `cargo check` under `crates/` never
+    // compiles but `staged-ci.yml` does.
     ExecuteFixOptions {
         command_override,
         npm_registry: crate::managed_acp_tools::npm_registry().map(str::to_string),
-        env: None,
+        ..Default::default()
     }
     .with_env_snapshot(env_vars)
 }

crates/doctor/src/command.rs

@@ -193,7 +193,11 @@ fn clean_up_after_incomplete_wait(child: &mut Child) {
     let _ = child.wait();
 }
 
-fn kill_child_process_group_or_child(child: &mut Child) {
+/// Best-effort kill: target the child's process group first so a shell's whole
+/// command tree goes with it, falling back to the direct child when the group
+/// lookup fails (the child wasn't spawned with `process_group(0)`, or it isn't
+/// Unix). Callers must still reap afterwards.
+pub(crate) fn kill_child_process_group_or_child(child: &mut Child) {
     if kill_child_process_group(child) {
         return;
     }