Fix Codex lifecycle hooks on Windows and support 32 project floors

[schnepg1]

Change

Codex lifecycle hook commands currently use POSIX shell quoting on Windows. Launch the helper through an encoded PowerShell command on win32 so it works from both PowerShell and Command Prompt, including paths with spaces, apostrophes and shell metacharacters. Other platforms keep their existing quoting.

Adds a Windows execution test covering stdin forwarding and authenticated lifecycle events through both shells. Also increases the project floor limit from 16 to 32 and documents both behaviors.

Based on upstream main at 7f7211e. The already merged npm run dev startup fix (#224) is included in the base; this PR addresses a separate Codex hook issue. The public lobby feature is a separate PR.

Validation

• Windows, Node 24.12.0: typecheck and production build pass.
• All 10 focused Codex and source size tests pass on this branch, including executing the hook through cmd.exe and powershell.exe.
• Combined local integration with the public lobby: all 22 focused tests pass; the dev server starts successfully.
• The full Windows test suite in the combined integration reports two client registry failures and six building clone failures; the same named failures occur on unchanged upstream 7f7211e. Full-suite runs did not finish and were stopped, including a repeat with a 60-second test timeout. This is not a full-suite pass.

Draft pending the contributor's interactive testing and CI/review. No preceding issue was opened.