bsk screenshot fails: Failed to capture tab: image readback failed (Chrome 151 / ext 0.1.5 / CLI 0.1.9)

[BeiIF]

Environment

• OS: Windows 11 x64
• bsk CLI: 0.1.9
• BrowserSkill extension: 0.1.5
• Browser: Chrome 151.0.0.0

Bug
bsk screenshot always fails with exit code 3:

error: browser rejected the underlying CDP call
hint: confirm the tab is still in a loaded state and retry; reloading the tab usually resets a stuck DevTools session
details: Failed to capture tab: image readback failed

Steps to reproduce

1. bsk session start
2. bsk navigate https://github.com --session <id>
3. bsk screenshot --session <id> --out test.png

What works

• bsk doctor all OK (extension connected, protocol compatible)
• bsk navigate, bsk snapshot, bsk session stop all work normally

What I already tried

• Different pages (example.com, github.com) - same failure
• bsk reload then retry - same failure
• Full Chrome restart - same failure
• Launch Chrome with --disable-gpu - same failure
• Screenshot with and without --out

Expected
A PNG file is written to the output path.