Fix lingering cli process: Hard SIGKILL fallback

Author: uraimo

Sources/CodexBarCore/Host/Process/ProcessRegistry.swift

@@ -1,4 +1,9 @@
 import Foundation
+#if canImport(Darwin)
+import Darwin
+#else
+import Glibc
+#endif
 
 public final class ProcessRegistry: @unchecked Sendable {
     public static let shared = ProcessRegistry()
@@ -35,12 +40,32 @@ public final class ProcessRegistry: @unchecked Sendable {
         self.lock.unlock()
 
         for entry in active {
+            let pid = entry.process.processIdentifier
             if entry.process.isRunning {
                 entry.process.terminate()
             }
-            if let pgid = entry.processGroup {
+
+            if let pgid = entry.processGroup,
+               pgid > 0,
+               getpgid(pid) == pgid
+            {
                 kill(-pgid, SIGTERM)
             }
+
+            let waitDeadline = Date().addingTimeInterval(1.0)
+            while entry.process.isRunning, Date() < waitDeadline {
+                usleep(100_000)
+            }
+
+            if entry.process.isRunning {
+                if let pgid = entry.processGroup,
+                   pgid > 0,
+                   getpgid(pid) == pgid
+                {
+                    kill(-pgid, SIGKILL)
+                }
+                kill(pid, SIGKILL)
+            }
         }
     }
 }