diff --git a/docs/IMPLEMENTATION_HANDOFF.md b/docs/IMPLEMENTATION_HANDOFF.md
index 281ee84..9256cf6 100644
--- a/docs/IMPLEMENTATION_HANDOFF.md
+++ b/docs/IMPLEMENTATION_HANDOFF.md
@@ -108,6 +108,8 @@ pnpm --dir packages/update test
 - alpha 版本号改为取源码现有序号与 Nexus 远端序号的最大值后加一，禁止版本倒退和重复发布。
 - `#49` 被 Jenkins CPS 的不可序列化正则 Matcher 阻断；算法改为只保留整数，并从 Nexus group 读标签、向 hosted 写制品。
 - `#50` 证明旧 Jenkins 工作树仍保留 CRLF；主检出由 `CleanBeforeCheckout` 改为 `WipeWorkspace`，确保 `.gitattributes` 在全新工作树生效。
+- `XuqmRuntime.activate` 增加显式 `reloadBundle`：buz-only release 可替换旧定义并热加载；含 common 的 release 仍由宿主冷启动。
+- `#51` 通过换行、格式和类型门禁后，暴露 pack 校验脚本硬编码 Unix `npm`；现改为 `fileURLToPath` 与 Windows `cmd.exe/npm.cmd` 分支。
 
 ### 2026-07-17 / common 第一轮
 
diff --git a/packages/update/README.md b/packages/update/README.md
index 7a2400d..ba49f8e 100644
--- a/packages/update/README.md
+++ b/packages/update/README.md
@@ -37,6 +37,10 @@ apply from: file("../../node_modules/@xuqm/rn-update/android/xuqm-bundles.gradle
 
 ## 运行时规则
 
+安装仅包含 buz 的 release set 后，使用
+`XuqmRuntime.activate(moduleId, { reloadBundle: true })` 重新求值并激活新 bundle。若 release set
+包含 common，宿主必须冷启动，不能在同一 JavaScript VM 中混用新旧 common。
+
 ```ts
 import { UpdateSDK, XuqmRuntime } from '@xuqm/rn-update'
 
diff --git a/packages/update/scripts/verify-package.mjs b/packages/update/scripts/verify-package.mjs
index a3f720d..39e7e8c 100755
--- a/packages/update/scripts/verify-package.mjs
+++ b/packages/update/scripts/verify-package.mjs
@@ -4,15 +4,26 @@ import { execFileSync } from 'node:child_process'
 import { readFileSync, rmSync } from 'node:fs'
 import { tmpdir } from 'node:os'
 import path from 'node:path'
+import { fileURLToPath } from 'node:url'
 
-const cwd = new URL('..', import.meta.url).pathname
-const result = JSON.parse(
-  execFileSync('npm', ['pack', '--json', '--ignore-scripts'], {
-    cwd,
-    encoding: 'utf8',
-    env: { ...process.env, npm_config_cache: path.join(tmpdir(), 'xuqm-rn-npm-cache') },
-  }),
-)[0]
+const cwd = fileURLToPath(new URL('..', import.meta.url))
+const packOutput =
+  process.platform === 'win32'
+    ? execFileSync(
+        process.env.ComSpec ?? 'cmd.exe',
+        ['/d', '/s', '/c', 'npm.cmd pack --json --ignore-scripts'],
+        {
+          cwd,
+          encoding: 'utf8',
+          env: { ...process.env, npm_config_cache: path.join(tmpdir(), 'xuqm-rn-npm-cache') },
+        },
+      )
+    : execFileSync('npm', ['pack', '--json', '--ignore-scripts'], {
+        cwd,
+        encoding: 'utf8',
+        env: { ...process.env, npm_config_cache: path.join(tmpdir(), 'xuqm-rn-npm-cache') },
+      })
+const result = JSON.parse(packOutput)[0]
 const required = [
   'android/src/main/AndroidManifest.xml',
   'android/src/main/java/com/xuqm/update/XuqmBundleModule.java',
diff --git a/packages/update/src/PluginRuntime.ts b/packages/update/src/PluginRuntime.ts
index 1f82d02..0bafaf8 100644
--- a/packages/update/src/PluginRuntime.ts
+++ b/packages/update/src/PluginRuntime.ts
@@ -19,6 +19,11 @@ export interface XuqmRuntimeOptions {
   checkUpdatesOnStart?: boolean
 }
 
+export interface XuqmPluginActivationOptions {
+  /** Re-evaluate the active bundle after a buz-only release was installed. */
+  reloadBundle?: boolean
+}
+
 const definitions = new Map<string, XuqmPluginDefinition>()
 
 /** Called by a plugin bundle when it is evaluated. */
@@ -55,9 +60,19 @@ export const XuqmRuntime = (() => {
       return { kind: 'none' as const }
     },
 
-    async activate(moduleId: string): Promise<void> {
+    async activate(
+      moduleId: string,
+      activationOptions: XuqmPluginActivationOptions = {},
+    ): Promise<void> {
       if (!options) throw new Error('[XuqmRuntime] configure() must be called before activate()')
-      if (active.has(moduleId)) return
+      if (active.has(moduleId) && !activationOptions.reloadBundle) return
+
+      if (activationOptions.reloadBundle) {
+        const previous = definitions.get(moduleId)
+        if (previous?.deactivate) await previous.deactivate()
+        active.delete(moduleId)
+        definitions.delete(moduleId)
+      }
 
       let definition = definitions.get(moduleId)
       if (!definition) {
diff --git a/packages/update/src/index.ts b/packages/update/src/index.ts
index b85e0ff..54af458 100644
--- a/packages/update/src/index.ts
+++ b/packages/update/src/index.ts
@@ -20,4 +20,9 @@ export type {
   ReleaseSetPlan,
 } from './releaseSet'
 export { XuqmRuntime, definePlugin } from './PluginRuntime'
-export type { XuqmPluginContext, XuqmPluginDefinition, XuqmRuntimeOptions } from './PluginRuntime'
+export type {
+  XuqmPluginActivationOptions,
+  XuqmPluginContext,
+  XuqmPluginDefinition,
+  XuqmRuntimeOptions,
+} from './PluginRuntime'