diff --git a/src/core/cli-runner.ts b/src/core/cli-runner.ts
index 67f9839..ca4e645 100644
--- a/src/core/cli-runner.ts
+++ b/src/core/cli-runner.ts
@@ -1,8 +1,21 @@
 import { spawn } from "node:child_process";
 
+const MAX_OUTPUT_BYTES = 10 * 1024 * 1024;
+
+function cmdQuote(value: string): string {
+  // ponytail: minimal cmd.exe quoting for Windows .cmd shims; callers still pass argv, not shell text.
+  return `"${value.replace(/(["^&|<>()%!])/g, "^$1")}"`;
+}
+
 export function runCli(bin: string, args: string[], timeoutMs = 120_000): Promise<string> {
   return new Promise((resolve) => {
-    const child = spawn(bin, args, {
+    const isWin = process.platform === "win32";
+    const command = isWin ? "cmd.exe" : bin;
+    const commandArgs = isWin
+      ? ["/d", "/s", "/c", [cmdQuote(bin), ...args.map(cmdQuote)].join(" ")]
+      : args;
+
+    const child = spawn(command, commandArgs, {
       shell: false,
       timeout: timeoutMs,
       windowsHide: true,
@@ -10,13 +23,30 @@ export function runCli(bin: string, args: string[], timeoutMs = 120_000): Promis
 
     let stdout = "";
     let stderr = "";
-    child.stdout.on("data", (d) => { stdout += d.toString(); });
-    child.stderr.on("data", (d) => { stderr += d.toString(); });
+    let killedForOutput = false;
+    const append = (target: "stdout" | "stderr", chunk: Buffer) => {
+      if (stdout.length + stderr.length + chunk.length > MAX_OUTPUT_BYTES) {
+        killedForOutput = true;
+        child.kill();
+        return;
+      }
+      if (target === "stdout") stdout += chunk.toString();
+      else stderr += chunk.toString();
+    };
+
+    child.stdout.on("data", (d) => append("stdout", d));
+    child.stderr.on("data", (d) => append("stderr", d));
     child.on("error", (err) => resolve(`[CLI error: ${err.message.slice(0, 200)}]`));
     child.on("close", (code) => {
-      const out = stdout.trim();
-      if (out) resolve(out);
-      else resolve(`[CLI exited ${code ?? "unknown"}: ${stderr.slice(0, 200) || "no output"}]`);
+      if (killedForOutput) {
+        resolve(`[CLI error: output exceeded ${MAX_OUTPUT_BYTES} bytes]`);
+        return;
+      }
+      if (code === 0) {
+        resolve(stdout.trim());
+        return;
+      }
+      resolve(`[CLI exited ${code ?? "unknown"}: ${(stderr || stdout).slice(0, 400) || "no output"}]`);
     });
   });
 }