fix(test): add global preload for session state reset

bunfig.toml

@@ -0,0 +1,2 @@
+[test]
+preload = ["./test-setup.ts"]

test-setup.ts

@@ -0,0 +1,6 @@
+import { beforeEach } from "bun:test"
+import { _resetForTesting } from "./src/features/claude-code-session-state/state"
+
+beforeEach(() => {
+  _resetForTesting()
+})