fix: preserve child process signal exit codes (#113685)

Co-authored-by: Peter Steinberger <steipete@golden-gate.local>

src/cli/proxy-cli.runtime.ts

@@ -22,6 +22,7 @@ import {
   getDebugProxyCaptureStore,
 } from "../proxy-capture/store.sqlite.js";
 import type { CaptureQueryPreset } from "../proxy-capture/types.js";
+import { resolveSubprocessExitCode } from "./subprocess-exit-code.js";
 
 export async function runDebugProxyStartCommand(opts: { host?: string; port?: number }) {
   const settings = resolveDebugProxySettings();
@@ -108,7 +109,7 @@ export async function runDebugProxyRunCommand(opts: {
       });
       child.once("error", reject);
       child.once("exit", (code, signal) => {
-        process.exitCode = signal ? 1 : (code ?? 1);
+        process.exitCode = resolveSubprocessExitCode(code, signal);
         resolve();
       });
     });