[navigation menu] Support click-only or mixed trigger modes for item activation

# Feature request

## Summary

Add support for activating `NavigationMenu.Item` via **click only**, not just hover or hover+click. Ideally, allow configuring individual triggers to respond to either hover, click, or both. This would provide more control and flexibility in building complex navigation patterns.

For example, some menu items might require explicit user intent (click-only), while others benefit from faster access via hover or combined interaction.

## Examples in other libraries

Radix UI's related issue: [radix-ui/primitives#1630](https://github.com/radix-ui/primitives/issues/1630)

## Motivation

I'm building a menu with mixed interaction models — some items should open on **click only**, while others can open on **hover or click**. Currently, `NavigationMenu` doesn't offer fine-grained control over interaction type per trigger.

Supporting this would enable more accessible, predictable navigation behaviors for complex UIs, such as:

- Large dropdowns that shouldn't open on accidental hover
- Menus with nested navigation requiring deliberate activation