fix(grok): prefix PowerShell call operator on Windows hook commands

[Dannym-Packetloss]

Summary

Grok runs hook commands through PowerShell (pwsh) on Windows. installGrokHooks() wrote "<hive-node.cmd>" "<grok-hook.cjs>"; in PowerShell a line that starts with a quoted string is an expression, so the second string is a ParserError (Unexpected token) and every hook exits 1. Grok ignores the failure, so tools run but the hive never gets status, session capture or tracking. Because the file is rewritten on every Grok spawn, a manual fix does not survive.

This adds grokHookCommand(), which puts PowerShell's call operator in front on win32: & "<hive-node.cmd>" "<grok-hook.cjs>". macOS/Linux output is unchanged.

Fixes #749

Tests

• New unit test for grokHookCommand() per platform.
• New Windows test that installs the Grok hooks under a hive path with a space and runs the generated command in pwsh: the old shape fails with a ParserError (negative control), the new one exits 0.
• npm run typecheck clean; test/hive-hook-node.test.cjs: 11 pass, 0 fail, 3 skipped (POSIX only). npm run test:focused adds 2 passing tests and no new failures.
• Tested on Windows 11, pwsh 7.6.6, Grok 1.0.52.

Before

The generated hook command, run by pwsh 7.6.6 as Grok runs it:

PS> "%APPDATA%\munder-difflin\shared\bin\<hash>\hive-node.cmd" "%APPDATA%\munder-difflin\shared\bin\<hash>\grok-hook.cjs"
ParserError:
Line |
   1 |  . e-node.cmd" "C:\Users\…\AppData\Roaming\munder-difflin\shared\bin .
     |                ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
     | Unexpected token '"…\grok-hook.cjs"' in expression or statement.
exit code: 1

After

PS> & "%APPDATA%\munder-difflin\shared\bin\<hash>\hive-node.cmd" "%APPDATA%\munder-difflin\shared\bin\<hash>\grok-hook.cjs"
exit code: 0

With this command in ~/.grok/hooks/munder-hive.json, Grok's Hooks tab shows global/munder-hive passing (pre_tool_use, post_tool_use, user_prompt_submit: status=success) where it previously failed every event.

🤖 Generated with Claude Code

[github-actions]

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