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 <[email protected]>

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> {