debug: add Windows CI debugging for optimize test failures

Add debug logging to help diagnose why optimize tests are failing
on Windows with exit code 1. This will show:
- Whether CI is detected correctly on Windows
- What install arguments are being passed to pnpm
- The state of environment variables

🤖 Generated with [Claude Code](https://claude.ai/code)

Co-Authored-By: Claude <noreply@anthropic.com>

Author: jdalton

src/utils/agent.mts

@@ -40,10 +40,22 @@ export function runAgentInstall(
   const skipNodeHardenFlags = isPnpm && pkgEnvDetails.agentVersion.major < 11
   // In CI mode, pnpm uses --frozen-lockfile by default, which prevents lockfile updates.
   // We need to explicitly disable it when updating the lockfile with overrides.
-  const installArgs = isPnpm && constants.ENV.CI
+  const isCi = constants.ENV.CI
+  const installArgs = isPnpm && isCi
     ? ['install', '--no-frozen-lockfile', ...args]
     : ['install', ...args]
 
+  // Debug logging for Windows CI issues.
+  if (constants.WIN32 && (isCi || process.env.SOCKET_CLI_DEBUG)) {
+    console.error(`[DEBUG] Windows runAgentInstall:`)
+    console.error(`  agent: ${agent}`)
+    console.error(`  isPnpm: ${isPnpm}`)
+    console.error(`  isCi: ${isCi}`)
+    console.error(`  constants.ENV.CI: ${constants.ENV.CI}`)
+    console.error(`  process.env.CI: ${process.env.CI}`)
+    console.error(`  installArgs: ${JSON.stringify(installArgs)}`)
+  }
+
   return spawn(agentExecPath, installArgs, {
     cwd: pkgPath,
     shell: constants.WIN32,