fix(process): Spawn child processes without a console window (#17)

- The IDE is a GUI-subsystem binary, so Windows allocated a fresh console
  window for every console-subsystem child it started: one black window per
  language server, per settings-driven restart, per debug adapter and per
  toolchain probe, titled with the child's own path. Closing it killed the
  child, which is how editing the language-server settings broke highlighting.
- Peer::spawn, the spawn point for every language server, wired stdio but never
  passed CREATE_NO_WINDOW. The rustup-proxy probe, the DAP adapter, debugpy
  probe, runInTerminal and cargo spawns, the SDK probes, the run-configuration
  probes, the coverage exporter and tool diagnostics/downloads (curl, tar) had
  the same gap, while git, cargo builds, gh, docker and run configurations
  passed the flag inline — five copies of the magic constant, six subsystems
  without it.
- Add ide_core::process::{CREATE_NO_WINDOW, hide_console_window} as the single
  definition, route every spawn through it (tokio commands via as_std_mut()) and
  fold the inline copies into it.
- Verified locally on Windows with a console-detached harness: a plain spawn
  reports a visible console window (GetConsoleWindow + IsWindowVisible), the
  patched Peer::spawn reports a console without a window. cargo check, cargo
  clippy --all-targets and the affected test suites (249 tests) are green.

Co-authored-by: l0ng-ai <24760907+l0ng-ai@users.noreply.github.com>

crates/ide-build/src/process.rs

@@ -52,12 +52,7 @@ pub(crate) fn run(
         use std::os::unix::process::CommandExt;
         command.process_group(0);
     }
-    #[cfg(windows)]
-    {
-        use std::os::windows::process::CommandExt;
-        const CREATE_NO_WINDOW: u32 = 0x0800_0000;
-        command.creation_flags(CREATE_NO_WINDOW);
-    }
+    ide_core::process::no_window(&mut command);
     let mut child = command.spawn().map_err(|e| IdeError::unavailable(format!("cannot start {program}: {e}")))?;
     let (tx, rx) = mpsc::channel::<(Stream, String)>();
     let pump = |stream: Box<dyn Read + Send>, kind: Stream, tx: mpsc::Sender<(Stream, String)>| {

crates/ide-core/src/process.rs

@@ -2,6 +2,10 @@
 
 use std::process::Command;
 
+/// Windows `CREATE_NO_WINDOW` creation flag, for call sites that combine it
+/// with other flags. Prefer [`no_window`] otherwise.
+pub const CREATE_NO_WINDOW: u32 = 0x0800_0000;
+
 /// Keeps a console child (java, node, curl, a language server, ...) from
 /// opening its own console window on Windows. Release builds use the GUI
 /// subsystem, so without this every spawn flashes a `cmd` window. A no-op
@@ -10,7 +14,6 @@ pub fn no_window(cmd: &mut Command) -> &mut Command {
     #[cfg(windows)]
     {
         use std::os::windows::process::CommandExt;
-        const CREATE_NO_WINDOW: u32 = 0x0800_0000;
         cmd.creation_flags(CREATE_NO_WINDOW);
     }
     cmd

crates/ide-docker/src/process.rs

@@ -25,11 +25,7 @@ fn prepare(cmd: &mut Command) {
         use std::os::unix::process::CommandExt;
         cmd.process_group(0);
     }
-    #[cfg(windows)]
-    {
-        use std::os::windows::process::CommandExt;
-        cmd.creation_flags(0x0800_0000);
-    }
+    ide_core::process::no_window(cmd);
 }
 
 fn spawn(cmd: &mut Command) -> IdeResult<Child> {

crates/ide-github/src/process.rs

@@ -25,11 +25,7 @@ fn prepare(cmd: &mut Command) {
         use std::os::unix::process::CommandExt;
         cmd.process_group(0);
     }
-    #[cfg(windows)]
-    {
-        use std::os::windows::process::CommandExt;
-        cmd.creation_flags(0x0800_0000);
-    }
+    ide_core::process::no_window(cmd);
 }
 
 fn spawn(cmd: &mut Command) -> IdeResult<Child> {

crates/ide-run/src/process.rs

@@ -205,8 +205,7 @@ impl ProcessManager {
         {
             use std::os::windows::process::CommandExt;
             const CREATE_NEW_PROCESS_GROUP: u32 = 0x0000_0200;
-            const CREATE_NO_WINDOW: u32 = 0x0800_0000;
-            cmd.creation_flags(CREATE_NEW_PROCESS_GROUP | CREATE_NO_WINDOW);
+            cmd.creation_flags(CREATE_NEW_PROCESS_GROUP | ide_core::process::CREATE_NO_WINDOW);
         }
 
         let mut child = cmd.spawn().map_err(|e| match e.kind() {
@@ -400,7 +399,7 @@ fn kill_tree(pid: u32, _force: bool) {
     // Console children have no reliable graceful signal from outside their console.
     let _ = Command::new("taskkill")
         .args(["/T", "/F", "/PID", &pid.to_string()])
-        .creation_flags(0x0800_0000)
+        .creation_flags(ide_core::process::CREATE_NO_WINDOW)
         .stdout(Stdio::null())
         .stderr(Stdio::null())
         .status();

crates/ide-vcs/src/cli.rs

@@ -64,11 +64,7 @@ pub fn git_version(executable: Option<&Path>) -> IdeResult<String> {
     };
     let mut cmd = Command::new(&exe);
     cmd.arg("--version").stdin(Stdio::null()).env("LC_ALL", "C");
-    #[cfg(windows)]
-    {
-        use std::os::windows::process::CommandExt;
-        cmd.creation_flags(0x0800_0000);
-    }
+    ide_core::process::no_window(&mut cmd);
     let out = cmd.output().map_err(|e| IdeError::unavailable(format!("cannot run {}: {e}", exe.display())))?;
     let text = String::from_utf8_lossy(&out.stdout).trim().to_string();
     if !out.status.success() || !text.starts_with("git version") {
@@ -99,12 +95,7 @@ pub(crate) fn command(root: &Path) -> IdeResult<Command> {
         .env_remove("GIT_DIR")
         .env_remove("GIT_WORK_TREE")
         .env_remove("GIT_INDEX_FILE");
-    #[cfg(windows)]
-    {
-        use std::os::windows::process::CommandExt;
-        const CREATE_NO_WINDOW: u32 = 0x0800_0000;
-        cmd.creation_flags(CREATE_NO_WINDOW);
-    }
+    ide_core::process::no_window(&mut cmd);
     Ok(cmd)
 }