chore: import upstream snapshot with attribution

tests/unit/processManager.test.ts

@@ -0,0 +1,43 @@
+import { describe, it } from "node:test";
+import assert from "node:assert/strict";
+
+describe("processManager", () => {
+  let mod;
+  it("should load module", async () => {
+    const loadPromise = import("../../src/lib/versionManager/processManager.ts");
+    const timeoutPromise = new Promise((_, reject) =>
+      setTimeout(() => reject(new Error("Module load timeout")), 5000)
+    );
+    mod = await Promise.race([loadPromise, timeoutPromise]);
+    assert.ok(mod);
+  });
+
+  it("should export expected functions", () => {
+    assert.equal(typeof mod.startProcess, "function");
+    assert.equal(typeof mod.isProcessRunning, "function");
+    assert.equal(typeof mod.stopProcess, "function");
+    assert.equal(typeof mod.restartProcess, "function");
+    assert.equal(typeof mod.getProcessInfo, "function");
+  });
+
+  it("isProcessRunning should return false for large invalid PID", () => {
+    assert.equal(mod.isProcessRunning(999999999), false);
+  });
+
+  it("isProcessRunning should return true for current process", () => {
+    assert.equal(mod.isProcessRunning(process.pid), true);
+  });
+
+  it("stopProcess should resolve immediately for non-running PID", async () => {
+    const start = Date.now();
+    await mod.stopProcess(999999999);
+    assert.ok(Date.now() - start < 1000);
+  });
+
+  it("getProcessInfo should return alive=false for invalid PID", async () => {
+    const info = await mod.getProcessInfo(999999999);
+    assert.equal(info.pid, 999999999);
+    assert.equal(info.alive, false);
+    assert.equal(info.memoryUsage, undefined);
+  });
+});