fix: tag search parsing and shell-safe ripgrep globs

[guitmz]

This fixes the tag search flow so tags behave the way Grove documents and users expect.

• parse inline #hashtags into note metadata, not just #+filetags:
• merge inline hashtags with #+filetags: without duplicates
• normalize tag input in grove-search-tag
• escape tag input before building the ripgrep regex
• quote --glob='*.org' in shell-built ripgrep commands so fallback search/backlink commands work correctly under zsh

[jonathanchu]

Thanks @guitmz ! Great catches here. These are definite bugs I did not catch, much appreciated!

One small note, I don't have ERT workflows in GitHub Actions yet but that will be something to add up next. Happy to merge as-is though. Thank you again!