feat(code): add useComboboxFilter hook to improve branch and repo picker performance

[VojtechBartos]

Problem

The branch selector combobox was slow to open on repos with many branches. cmdk renders every item as a DOM node (no virtualization), and each ComboboxItem carries significant per-instance overhead (Tooltip, refs, effects). With hundreds of branches, opening the picker caused a noticeable lag.

Solution

Instead of rendering all items and letting cmdk filter via display: none, we:

1. Disable cmdk's built-in filtering (shouldFilter={false})
2. Let cmdk manage the input natively (uncontrolled)
3. Listen for search changes via onValueChange and debounce them
4. Score items with cmdk's own defaultFilter (fuzzy matching), filter out noise below a 0.1 threshold, and cap rendered results at 50

Applying it to branch combobox and also to github repo combobox

Showcase

code-filtering.mov

[adboio]

can we build this as a wrapper on ComboBox.Content so future devs don't have to remember (or be aware of) these requirements?

[VojtechBartos]

yeah, sure :) you would like to see it as part of the ComboBox.Content or just new component like ComboBox.FilteredContent?

[adboio]

thank you!!

i think either way is fine by me :) just something to make it a little smoother and less likely that someone forgets to do this, since it seems to be a nice perf improvement all around

[VojtechBartos]

@adboio see latest commit if looks good ;)

[adboio]

beautiful, thank you!!!