diff --git a/web/hwlab-cloud-web/package.json b/web/hwlab-cloud-web/package.json
index 0ca7915e..bbed1ff6 100644
--- a/web/hwlab-cloud-web/package.json
+++ b/web/hwlab-cloud-web/package.json
@@ -13,6 +13,7 @@
     "caserun:native:status": "bun run scripts/caserun-native-service.ts status",
     "caserun:native:logs": "bun run scripts/caserun-native-service.ts logs",
     "caserun:native:smoke": "bun run scripts/caserun-native-smoke.ts",
+    "caserun:native:reload-smoke": "bun run scripts/caserun-native-reload-smoke.ts",
     "check": "bun run deps --quiet && bun run scripts/tsc-check.ts && bun test scripts",
     "check:tsc": "bun run deps --quiet && bun run scripts/tsc-check.ts",
     "check:tsc-strict": "bun run deps --quiet && bun run scripts/tsc-check.ts --strict",
diff --git a/web/hwlab-cloud-web/scripts/caserun-native-reload-smoke.ts b/web/hwlab-cloud-web/scripts/caserun-native-reload-smoke.ts
new file mode 100644
index 00000000..1cb2fe85
--- /dev/null
+++ b/web/hwlab-cloud-web/scripts/caserun-native-reload-smoke.ts
@@ -0,0 +1,129 @@
+import { readFileSync, renameSync, rmSync, statSync, utimesSync } from "node:fs";
+import { resolve } from "node:path";
+
+const root = process.cwd();
+const watchedPath = resolve(root, "scripts/caserun-native-fixtures.ts");
+const displacedPath = `${watchedPath}.reload-smoke`;
+const originalStat = statSync(watchedPath);
+const port = Number(process.env.HWLAB_CASERUN_RELOAD_SMOKE_PORT || 14316);
+const baseUrl = `http://127.0.0.1:${port}`;
+const reloadEvents: Array<{ pid?: number; reason?: string }> = [];
+let output = "";
+let displaced = false;
+
+function requireCondition(condition: unknown, message: string): asserts condition {
+  if (!condition) throw new Error(message);
+}
+
+async function waitFor(description: string, condition: () => boolean | Promise<boolean>, timeoutMs = 5000): Promise<void> {
+  const deadline = Date.now() + timeoutMs;
+  while (Date.now() < deadline) {
+    if (await condition()) return;
+    await Bun.sleep(50);
+  }
+  throw new Error(`timeout waiting for ${description}`);
+}
+
+async function readOutput(stream: ReadableStream<Uint8Array>): Promise<void> {
+  const reader = stream.getReader();
+  const decoder = new TextDecoder();
+  let pending = "";
+  while (true) {
+    const { done, value } = await reader.read();
+    if (done) break;
+    const chunk = decoder.decode(value, { stream: true });
+    output += chunk;
+    pending += chunk;
+    const lines = pending.split("\n");
+    pending = lines.pop() || "";
+    for (const line of lines) {
+      if (!line.includes('"event":"caserun-native-reload"')) continue;
+      const event = JSON.parse(line) as { pid?: number; reason?: string };
+      if (!reloadEvents.some((existing) => existing.pid === event.pid)) reloadEvents.push(event);
+    }
+  }
+  const finalChunk = decoder.decode();
+  output += finalChunk;
+  pending += finalChunk;
+  if (pending.includes('"event":"caserun-native-reload"')) {
+    const event = JSON.parse(pending) as { pid?: number; reason?: string };
+    if (!reloadEvents.some((existing) => existing.pid === event.pid)) reloadEvents.push(event);
+  }
+}
+
+async function healthAvailable(): Promise<boolean> {
+  try {
+    const response = await fetch(`${baseUrl}/health`);
+    return response.ok;
+  } catch {
+    return false;
+  }
+}
+
+function childPids(supervisorPid: number): number[] {
+  try {
+    return readFileSync(`/proc/${supervisorPid}/task/${supervisorPid}/children`, "utf8")
+      .trim()
+      .split(/\s+/)
+      .filter(Boolean)
+      .map(Number);
+  } catch {
+    return [];
+  }
+}
+
+rmSync(displacedPath, { force: true });
+const supervisor = Bun.spawn([process.execPath, "scripts/caserun-native-supervisor.ts"], {
+  cwd: root,
+  env: { ...process.env, HWLAB_CASERUN_NATIVE_PORT: String(port) },
+  stdin: "ignore",
+  stdout: "pipe",
+  stderr: "pipe"
+});
+const stdoutTask = readOutput(supervisor.stdout);
+const stderrTask = readOutput(supervisor.stderr);
+
+try {
+  await waitFor("initial native health", healthAvailable);
+
+  renameSync(watchedPath, displacedPath);
+  displaced = true;
+  await Bun.sleep(300);
+  requireCondition(supervisor.exitCode === null, `supervisor exited during atomic save window: ${supervisor.exitCode}`);
+  renameSync(displacedPath, watchedPath);
+  displaced = false;
+  const restoredAt = new Date(Date.now() + 1000);
+  utimesSync(watchedPath, restoredAt, restoredAt);
+  await waitFor("reload after atomic save", () => reloadEvents.length >= 2);
+
+  for (let index = 0; index < 5; index += 1) {
+    const changedAt = new Date(Date.now() + (index + 1) * 1000);
+    utimesSync(watchedPath, changedAt, changedAt);
+    await Bun.sleep(120);
+  }
+
+  await waitFor("final native health", healthAvailable);
+  await Bun.sleep(300);
+  const liveChildren = childPids(supervisor.pid);
+  requireCondition(liveChildren.length === 1, `expected one native server child, found ${liveChildren.join(",") || "none"}`);
+  requireCondition(reloadEvents.length >= 3, `expected repeated reloads, found ${reloadEvents.length}`);
+  requireCondition(!output.includes("EADDRINUSE"), "native reload logged EADDRINUSE");
+
+  console.log(JSON.stringify({
+    ok: true,
+    mode: "native-test",
+    supervisorPid: supervisor.pid,
+    serverPid: liveChildren[0],
+    reloadCount: reloadEvents.length,
+    reloadPids: reloadEvents.map((event) => event.pid),
+    atomicSaveMissingFileTolerated: true,
+    eaddrinuse: false
+  }));
+} finally {
+  if (displaced) renameSync(displacedPath, watchedPath);
+  rmSync(displacedPath, { force: true });
+  utimesSync(watchedPath, originalStat.atime, originalStat.mtime);
+  if (supervisor.exitCode === null) supervisor.kill("SIGTERM");
+  await supervisor.exited;
+  await Promise.all([stdoutTask, stderrTask]);
+}
diff --git a/web/hwlab-cloud-web/scripts/caserun-native-service.ts b/web/hwlab-cloud-web/scripts/caserun-native-service.ts
index e017fbbb..91871105 100644
--- a/web/hwlab-cloud-web/scripts/caserun-native-service.ts
+++ b/web/hwlab-cloud-web/scripts/caserun-native-service.ts
@@ -26,6 +26,15 @@ function isRunning(pid: number | null): boolean {
   }
 }
 
+async function waitForExit(pid: number): Promise<boolean> {
+  const deadline = Date.now() + 5000;
+  while (Date.now() < deadline) {
+    if (!isRunning(pid)) return true;
+    await Bun.sleep(25);
+  }
+  return !isRunning(pid);
+}
+
 mkdirSync(stateDir, { recursive: true });
 const pid = readPid();
 
@@ -46,8 +55,12 @@ if (action === "start") {
     console.log(JSON.stringify({ ok: true, action, status: "stopped" }));
   } else {
     process.kill(pid!, "SIGTERM");
+    if (!await waitForExit(pid!)) {
+      console.error(JSON.stringify({ ok: false, action, status: "stop-timeout", pid }));
+      process.exit(1);
+    }
     rmSync(pidPath, { force: true });
-    console.log(JSON.stringify({ ok: true, action, status: "stopping", pid }));
+    console.log(JSON.stringify({ ok: true, action, status: "stopped", pid }));
   }
 } else if (action === "status") {
   const running = isRunning(pid);
diff --git a/web/hwlab-cloud-web/scripts/caserun-native-supervisor.ts b/web/hwlab-cloud-web/scripts/caserun-native-supervisor.ts
index e470c17a..7c5603fc 100644
--- a/web/hwlab-cloud-web/scripts/caserun-native-supervisor.ts
+++ b/web/hwlab-cloud-web/scripts/caserun-native-supervisor.ts
@@ -10,40 +10,62 @@ const watchedFiles = [
 let child: ReturnType<typeof Bun.spawn> | null = null;
 let signature = sourceSignature();
 let stopping = false;
+let restarting = false;
 
-function sourceSignature(): string {
-  return watchedFiles.map((path) => `${path}:${statSync(path).mtimeMs}:${statSync(path).size}`).join("|");
+function sourceSignature(): string | null {
+  try {
+    return watchedFiles.map((path) => {
+      const source = statSync(path);
+      return `${path}:${source.mtimeMs}:${source.size}`;
+    }).join("|");
+  } catch (error) {
+    if (error instanceof Error && "code" in error && error.code === "ENOENT") return null;
+    throw error;
+  }
 }
 
 function startChild(reason: string): void {
-  child = Bun.spawn([process.execPath, "scripts/caserun-native-server.ts"], { cwd: root, stdin: "ignore", stdout: "inherit", stderr: "inherit" });
-  console.log(JSON.stringify({ event: "caserun-native-reload", mode: "native-test", reason, pid: child.pid }));
-  void child.exited.then((exitCode) => {
-    if (!stopping && child?.exitCode === exitCode) console.log(JSON.stringify({ event: "caserun-native-exit", exitCode }));
+  const spawned = Bun.spawn([process.execPath, "scripts/caserun-native-server.ts"], { cwd: root, stdin: "ignore", stdout: "inherit", stderr: "inherit" });
+  child = spawned;
+  console.log(JSON.stringify({ event: "caserun-native-reload", mode: "native-test", reason, pid: spawned.pid }));
+  void spawned.exited.then((exitCode) => {
+    if (!stopping && child === spawned) console.log(JSON.stringify({ event: "caserun-native-exit", exitCode }));
   });
 }
 
-function stopChild(): void {
-  if (child && child.exitCode === null) child.kill("SIGTERM");
-  child = null;
+async function stopChild(): Promise<void> {
+  const runningChild = child;
+  if (!runningChild) return;
+  if (runningChild.exitCode === null) runningChild.kill("SIGTERM");
+  await runningChild.exited;
+  if (child === runningChild) child = null;
 }
 
 startChild("initial");
 
-const timer = setInterval(() => {
+async function reloadIfChanged(): Promise<void> {
+  if (stopping || restarting) return;
   const nextSignature = sourceSignature();
-  if (nextSignature === signature) return;
+  if (nextSignature === null || nextSignature === signature) return;
   signature = nextSignature;
-  stopChild();
-  startChild("source-change");
-}, 500);
+  restarting = true;
+  try {
+    await stopChild();
+    if (!stopping) startChild("source-change");
+  } finally {
+    restarting = false;
+  }
+}
 
-function shutdown(): void {
+const timer = setInterval(() => void reloadIfChanged(), 100);
+
+async function shutdown(): Promise<void> {
+  if (stopping) return;
   stopping = true;
   clearInterval(timer);
-  stopChild();
+  await stopChild();
   process.exit(0);
 }
 
-process.on("SIGINT", shutdown);
-process.on("SIGTERM", shutdown);
+process.on("SIGINT", () => void shutdown());
+process.on("SIGTERM", () => void shutdown());