fix: use unique workspace per command execution (fixes #1114)

[kagura-agent]

Summary

Fix concurrent commands for the same site failing with Detached while handling command.

Closes #1114

Root Cause

Browser command execution uses a workspace key based only on site name (site:${cmd.site}). When two commands for the same site run concurrently, they share the same browser session. If one finishes first and calls page.closeWindow(), the other command's page is detached mid-execution.

Fix

Append crypto.randomUUID() to the workspace key so each command gets its own isolated browser session:

// Before
workspace: \`site:\${cmd.site}\`

// After  
workspace: \`site:\${cmd.site}:\${crypto.randomUUID()}\`

Testing

• All 1767 existing tests pass
• npx tsc --noEmit clean
• Surgical 1-line change in src/execution.ts

[Henry-G-H-Huang]

any update about this PR ?

[kagura-agent]

Hi @Henry-G-H-Huang — thanks for the ping! The PR is still up to date and mergeable. Waiting on maintainer review. Let me know if there's anything I can help with!