Harden desktop recovery and pre-release stability checks

Bound IPC transport deadlines while preserving portal leases, supervise desktop helper and agent recovery, and reserve final floating window geometry during placement.

Stabilize CLI output and isolated tests, expand workspace CI, resolve formatting and lint failures, and bundle the MIT license with installer compatibility.

compositor/src/process.rs

@@ -15,6 +15,9 @@ use tracing::{info, warn};
 use crate::Ferese;
 use crate::private_client::{self, ClientCapabilities};
 
+mod supervisor;
+pub(crate) use supervisor::Supervisor;
+
 pub(crate) fn command(program: impl AsRef<OsStr>) -> Command {
     let mut command = Command::new(program);
     // Calloop blocks these on the compositor thread; fork/exec inherits that
@@ -41,6 +44,15 @@ pub(crate) fn spawn_client<S: AsRef<OsStr>>(
     state: &mut Ferese,
     args: impl IntoIterator<Item = S>,
     capabilities: ClientCapabilities,
+) -> Option<Child> {
+    spawn_client_inner(state, args, capabilities, None)
+}
+
+fn spawn_client_inner<S: AsRef<OsStr>>(
+    state: &mut Ferese,
+    args: impl IntoIterator<Item = S>,
+    capabilities: ClientCapabilities,
+    supervised_restart: Option<bool>,
 ) -> Option<Child> {
     let mut args = args.into_iter();
     let Some(program) = args.next() else {
@@ -51,6 +63,10 @@ pub(crate) fn spawn_client<S: AsRef<OsStr>>(
     let program = program.as_ref();
     let mut command = command(program);
     command.args(args);
+    if let Some(restarted) = supervised_restart {
+        command.process_group(0);
+        command.env("FERESE_CLIENT_RESTART", if restarted { "1" } else { "0" });
+    }
     // Workers may already exist. Change only this child's environment.
     // Apply before granting the child a private Wayland connection.
     state.session_environment.apply_public(&mut command);