Step 2: the telemetry seam

ITelemetrySink with the null, log and JSON Lines sinks, FTelemetryEvent and the envelope, TelemetryEvents,
UTelemetrySubsystem on the game instance, ASaltyGameMode minting the session id into the replicated
ASaltyGameState, bs.TelemetryTest, the git hash in the build string (D-42) and four Salty.Core.Telemetry tests
replacing the placeholder. Proved standalone and with a headless server plus client sharing one session id.

Also enables the engine's Editor, AutomationTest, GameplayTags, ConfigSettings and LiveCoding MCP toolsets
(D-43) so the editor's MCP server exposes more than the skills toolset.

Co-Authored-By: Claude Fable 5.1 <noreply@anthropic.com>

Source/Salty/Core/SaltyGameMode.cpp

@@ -0,0 +1,23 @@
+#include "Core/SaltyGameMode.h"
+#include "Core/SaltyGameState.h"
+#include "Salty.h"
+
+ASaltyGameMode::ASaltyGameMode()
+{
+	GameStateClass = ASaltyGameState::StaticClass();
+}
+
+void ASaltyGameMode::InitGameState()
+{
+	Super::InitGameState();
+
+	ASaltyGameState* SaltyGameState = GetGameState<ASaltyGameState>();
+	if (!SaltyGameState)
+	{
+		// A Blueprint child that overrode GameStateClass with something else. Loud, because every telemetry
+		// file of this session would then be sessionless.
+		UE_LOG(LogSalty, Error, TEXT("%s: GameStateClass is not an ASaltyGameState; no session id will be minted"), *GetName());
+		return;
+	}
+	SaltyGameState->SetSessionId(FGuid::NewGuid());
+}