[rmarganti]

Summary

• Replace the deprecated vim.validate(spec) calls in Hydra initialization with the current argument-based signature.
• Preserve optional fields, accepted types, and custom validation messages.

Verification

• Loaded the fork in Neovim 0.12.1 and confirmed Hydra mappings are registered.
• Checked valid and invalid Hydra configurations; no deprecated vim.validate calls were emitted.

This overlaps with #72; this PR is an alternative implementation of the same fix.

[rmarganti]

Closing this duplicate in favor of #72. I will keep this change in my fork for my Neovim config.