diff --git a/README.md b/README.md
index ff5e22c7f..b6229b1b9 100644
--- a/README.md
+++ b/README.md
@@ -422,6 +422,7 @@ Broker and background-job lifecycle:
 | [#728](https://github.com/openai/codex-plugin-cc/pull/728) | a job whose worker died no longer reads as "running" forever; `/codex:status` reconciles the record against the live process |
 | [#725](https://github.com/openai/codex-plugin-cc/pull/725) | nothing is spawned through the user's shell on Windows, where MSYS path conversion mangled switches like `taskkill /PID` and left background workers unkillable under Git Bash (this supersedes [#735](https://github.com/openai/codex-plugin-cc/pull/735)) |
 | [#656](https://github.com/openai/codex-plugin-cc/pull/656) | `/codex:cancel` exits non-zero when neither the turn interrupt nor the worker kill confirmed the job stopped, instead of reporting a cancellation nothing proved |
+| [#770](https://github.com/openai/codex-plugin-cc/pull/770) | `npm run build` works on Windows: npm runs scripts through cmd.exe, where `mkdir -p` made a stray `-p` directory and then failed every build after the first |
 
 Commands and flags:
 
diff --git a/package.json b/package.json
index 4216d1040..b2983bf5a 100644
--- a/package.json
+++ b/package.json
@@ -11,7 +11,7 @@
   "scripts": {
     "bump-version": "node scripts/bump-version.mjs",
     "check-version": "node scripts/bump-version.mjs --check",
-    "prebuild": "mkdir -p plugins/codex/.generated/app-server-types && codex app-server generate-ts --out plugins/codex/.generated/app-server-types",
+    "prebuild": "node -e \"require('node:fs').mkdirSync('plugins/codex/.generated/app-server-types',{recursive:true})\" && codex app-server generate-ts --out plugins/codex/.generated/app-server-types",
     "build": "tsc -p tsconfig.app-server.json",
     "test": "node --test tests/*.test.mjs"
   },
diff --git a/plugins/codex/scripts/session-lifecycle-hook.mjs b/plugins/codex/scripts/session-lifecycle-hook.mjs
index c491494d4..0e658b848 100644
--- a/plugins/codex/scripts/session-lifecycle-hook.mjs
+++ b/plugins/codex/scripts/session-lifecycle-hook.mjs
@@ -23,11 +23,12 @@ import { resolveWorkspaceRoot } from "./lib/workspace.mjs";
 export const SESSION_ID_ENV = "CODEX_COMPANION_SESSION_ID";
 const PLUGIN_DATA_ENV = "CLAUDE_PLUGIN_DATA";
 
-// The SessionEnd hook runs under a 5-second timeout (hooks.json). The
-// budgets below must sum comfortably under it: brokered turn interrupts
-// (identity waits are capped per job and reserve room for the interrupt
-// RPCs themselves), then a short exit grace for killed workers, then the
-// shutdown exchange with its one retry.
+// The SessionEnd hook runs under a 30-second timeout (hooks.json; SessionStart is the 5-second
+// one). The budgets below must sum comfortably under it: brokered turn interrupts (identity waits
+// are capped per job and reserve room for the interrupt RPCs themselves), then a short exit grace
+// for killed workers, then the shutdown exchange with its one retry. The default interrupt budget
+// is deliberately far below the hook timeout — the hook must return long before Claude Code stops
+// waiting — and CODEX_TURN_INTERRUPT_BUDGET_MS raises it for a workspace with many active jobs.
 const TURN_INTERRUPT_BUDGET_MS = turnInterruptBudgetMs();
 const TURN_IDENTITY_WAIT_MS = 500;
 const TURN_INTERRUPT_RESERVE_MS = 1000;