Claude Desktop updater unconditionally re-copies chrome-native-host.exe on launch, causing hard launch failure when Chrome holds an open native-messaging handle

Environment

• OS: Windows 11
• Claude Desktop package: MSIX
• Versions observed across the failing update sequence: 1.30096.1 → 1.30096.5
• Trigger: Google Chrome running with the bundled Claude extension (extension id fcoeoabgfenejglbffodgkkbkcdhcgfn) enabled

Summary
Claude Desktop's updater fails to launch the app with the error "another program is currently using this file" when Chrome's bundled Claude extension has an open native-messaging connection to chrome-native-host.exe.

Root cause
On every launch, the Claude Desktop updater unconditionally re-copies ChromeNativeHost\chrome-native-host.exe into the app's install/update directory instead of first checking whether the installed binary is already at the target version. If Chrome's bundled extension holds an open native-messaging connection to that host process, the OS holds a file lock on it for the life of the Chrome process — independent of whether any specific tab or window is open. This lock does not reliably release even when the extension is toggled disabled in chrome://extensions. When the updater's copy step hits that lock, it fails with a Windows EBUSY-style "file in use" error, and the entire Claude Desktop app refuses to launch.

Repro steps

1. Install Claude Desktop (MSIX) with the bundled Chrome native-messaging extension enabled in Chrome.
2. Open Chrome and let the extension establish a native-messaging connection.
3. With Chrome still running, launch or update Claude Desktop.
4. Observe: launch fails with "another program is using" chrome-native-host.exe.
5. Disabling the extension in chrome://extensions does not reliably clear the lock; fully closing Chrome is required — or killing just the chrome-native-host.exe process (not chrome.exe) also releases the lock without closing any tabs.

Suggested fix

• Version-check chrome-native-host.exe before copying — skip the copy if the installed binary already matches the target version.
• If a copy is genuinely required and the target is locked, retry with backoff or degrade gracefully rather than hard-failing the entire app launch.

Impact
Total inability to launch Claude Desktop while Chrome is running with the extension active, until the user closes Chrome (or kills the helper process) — not documented anywhere in the error message. This has recurred across multiple sessions on the same machine.