Refine timeout constants from validation feedback

Agent-Logs-Url: https://github.com/github/copilot-sdk-java/sessions/38b90523-b5be-4dbd-9d33-36361110399b

Co-authored-by: edburns <75821+edburns@users.noreply.github.com>

src/main/java/com/github/copilot/sdk/CliServerManager.java

@@ -30,6 +30,7 @@
 final class CliServerManager {
 
     private static final Logger LOG = Logger.getLogger(CliServerManager.class.getName());
+    private static final int STDERR_READER_JOIN_TIMEOUT_MS = 5000;
 
     private final CopilotClientOptions options;
     private final StringBuilder stderrBuffer = new StringBuilder();
@@ -254,7 +255,7 @@ private void awaitStderrReader() {
         Thread t = this.stderrThread;
         if (t != null) {
             try {
-                t.join(5000);
+                t.join(STDERR_READER_JOIN_TIMEOUT_MS);
             } catch (InterruptedException e) {
                 Thread.currentThread().interrupt();
             }

src/main/java/com/github/copilot/sdk/CopilotClient.java

@@ -76,7 +76,7 @@ public final class CopilotClient implements AutoCloseable {
      * shutdown via {@link #stop()}.
      */
     public static final int AUTOCLOSEABLE_TIMEOUT_SECONDS = 10;
-    private static final long FORCE_KILL_TIMEOUT_SECONDS = 10;
+    private static final int FORCE_KILL_TIMEOUT_SECONDS = 10;
     private final CopilotClientOptions options;
     private final CliServerManager serverManager;
     private final LifecycleEventManager lifecycleManager = new LifecycleEventManager();