fix(CI-CD): fix website dispatch client_payload as object

[baxyz]

Summary

• The "Trigger website update" step in release.yml was passing client_payload as a pre-serialized JSON string via --raw-field, which the repository_dispatch API rejects (HTTP 422: "client_payload" is not an object).
• Discovered when releasing dotfiles-sync v1.0.6: GHCR publish and the git tag succeeded, but the website dispatch silently failed (the step has continue-on-error: true, so the job still showed green).
• Fixed by using gh api's field[nested]=value bracket syntax to build client_payload as a real JSON object instead of a string.
• Manually re-ran the corrected dispatch for the missed dotfiles-sync v1.0.6 release so the website isn't left stale until the next release.

Test plan

• Verified the corrected gh api call succeeds against the real repos/helpers4/website/dispatches endpoint (used to backfill the missed dotfiles-sync v1.0.6 dispatch)
• Next automated release should show a successful "Trigger website update" step

🤖 Generated with Claude Code

[github-actions]

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📋 Pipeline Status

	Job	Status
✅	🧾 Conventional Commits	passing
✅	🧪 Feature Tests	passing
✅	🐚 ShellCheck	passing

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_{🤖 Generated by @helpers4 CI • 2026-07-19}