fix(diag): attach EventPipe observers after client startup

Starting dotnet-counters in the process-creation race can suspend the CLR before the graphical host creates its window. Wait for the guaranteed in-world boundary, then attach counters and contention tracing during the route's warm-up interval.

Co-Authored-By: Codex <noreply@openai.com>

tests/AcDream.App.Tests/Diagnostics/ConnectedR6SoakContractTests.cs

@@ -351,6 +351,13 @@ public sealed class ConnectedR6SoakContractTests
             "RuntimeCounters = if (-not $SkipRuntimeCounters) { $runtimeCounters } else { $null }",
             source,
             StringComparison.Ordinal);
+        AssertAppearsInOrder(
+            source,
+            "Wait-ForLogPattern $process $stdoutLog 'live: in world'",
+            "if (-not $SkipRuntimeCounters) {",
+            "Start-Process -FilePath 'dotnet-counters'",
+            "if ($CaptureContention) {",
+            "Start-Process -FilePath 'dotnet-trace'");
     }
 
     [Fact]

tools/run-connected-r6-soak.ps1

@@ -685,6 +685,11 @@ try {
         -RedirectStandardOutput $stdoutLog -RedirectStandardError $stderrLog -PassThru
     Write-Marker "launch pid=$($process.Id) commit=$commit session='$env:SESSIONNAME'"
 
+    $null = Wait-ForLogPattern $process $stdoutLog 'live: in world' 1 $LoginTimeoutSeconds
+    # Attach EventPipe observers only after normal CLR/client startup. Starting
+    # dotnet-counters in the process-creation race can suspend the runtime
+    # before the graphical host has created a window. The route's 15-second
+    # warm-up leaves ample time to attach before its first teleport.
     if (-not $SkipRuntimeCounters) {
         $counterArguments = @(
             'collect',
@@ -721,7 +726,6 @@ try {
         Write-Marker "contention-capture pid=$($traceProcess.Id)"
     }
 
-    $null = Wait-ForLogPattern $process $stdoutLog 'live: in world' 1 $LoginTimeoutSeconds
     # "live: first player position" is a recenter diagnostic, not a session
     # boundary: it is intentionally absent when the player's authoritative
     # first cell already matches the initial streaming center. The first