feat(search): add fzf engine with frecency tiebreak

[luizhcrocha]

Hi, @savedra1

I've made this to give users an option on search engine and search result optimization, so they can get the most out of the search feature, tweaking as they like.

The default is still charmbracelet/bubles backed by sahilm/fuzzy, but if the user want's he can choose to use junegunn/fzf by adding these to settings:

{
    "search": {
        "engine": "fzf",
        "algo": "v2",
        "caseSensitivity": "smart",
        "normalize": true,
        "tiebreak": ["score", "frecency", "index"]
    }
}

One thing that I think you might no like is that I changed func sanitizedFilter to a high-order function func buildFilter, because I thought that would make the code more concise.

Wrote with Claude Code help, not full on vibecoded (I know some people hate this). Test was all Claude Code though.

I tested and, for me, got exactly the result I wanted. Hope you and clipse users like it.

[luizhcrocha]

I'll close so i can use may main for a while, and reopen from a branch.