test: improve docker compose retry for transient network failures

Increase max retries from 1 to 2 and add a 5-second delay between
cleanup and retry to give Docker time to fully release network
resources. Addresses flaky LinuxUnicodeSpecialCharactersTest failures
where docker compose up gets "network not found" due to Docker daemon
race conditions when multiple compose projects are active.

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

Author: tippmar-nr

tests/Agent/IntegrationTests/ContainerIntegrationTests/Applications/ContainerApplication.cs

@@ -265,13 +265,19 @@ protected override void WaitForProcessToStartListening(bool captureStandardOutpu
 
         Console.WriteLine($"[{AppName} {DateTime.Now}] Did not find PID file matching {pidFilePath}. {(RemoteProcess.HasExited ? "Process exited" : "Wait timed out")}.");
 
-        // Retry once if compose exited quickly (often due to transient network creation issues)
-        if (RemoteProcess.HasExited && _startupAttempts == 0)
+        // Retry if compose exited quickly (often due to transient Docker network issues
+        // where the daemon hasn't fully released resources from a prior compose project).
+        const int maxRetries = 2;
+        if (RemoteProcess.HasExited && _startupAttempts < maxRetries)
         {
             _startupAttempts++;
-            Console.WriteLine($"[{AppName} {DateTime.Now}] Early compose exit detected. Retrying docker compose up (attempt {_startupAttempts}).");
+            Console.WriteLine($"[{AppName} {DateTime.Now}] Early compose exit detected. Retrying docker compose up (attempt {_startupAttempts} of {maxRetries}).");
             TestLogger?.WriteLine($"[{AppName}] Retrying docker compose up.");
             CleanupContainer();
+
+            // Give Docker time to fully release network resources before retrying
+            Thread.Sleep(TimeSpan.FromSeconds(5));
+
             try
             {
                 var startInfo = new ProcessStartInfo