Preserve literal static attributes when folding

[joshhanley]

The Scenario

A user has a Flux radio group bound to a nullable boolean property using Livewire's .boolean modifier. Without Blaze, selecting the false radio option updates the property to false as expected. With Blaze enabled, selecting the false option still behaves as truthy, so the property appears to always be true.

<flux:radio.group wire:model.boolean.live="testBoolean" variant="cards">
    <flux:radio value="true" label="here is true" />
    <flux:radio value="false" label="here is false" />
</flux:radio.group>

The Problem

Blaze folding resolves static attribute values through Attribute::getStaticValue() before rendering folded output. That method was converting any static true, false, or null string into the equivalent PHP value, even when the attribute was not bound.

That meant value="false" became boolean false during folded rendering and was omitted by the attribute bag. Flux radio elements generate a fallback value when no value attribute is present, so the false option ended up with a generated non-empty string instead of "false".

Meanwhile, value="true" became boolean true and rendered as value="value". Livewire's .boolean modifier therefore received non-empty strings for both options, causing the false option to behave as truthy.

The Solution

This changes folded static attribute resolution so unbound literal values are kept as strings instead of being treated as PHP constants. Now value="false" stays "false" during folding and renders the same way it does in Blade.

Fixes livewire/flux#2651

[github-actions]

Benchmark Result: Default

Attempt	Blade	Blaze	Improvement
#1	351.85ms	16.18ms	95.4%
#2	357.24ms	16.07ms	95.5%
#3	350.33ms	16.29ms	95.4%
#4	353.47ms	16.05ms	95.5%
#5	358.86ms	15.92ms	95.6%
#6	351.67ms	16.38ms	95.3%
#7	354.67ms	16.12ms	95.5%
#8	345.44ms	15.96ms	95.4%
#9	353.23ms	15.98ms	95.5%
#10	349.94ms	16.01ms	95.4%
Snapshot	351.41ms	16.18ms	95.4%
Result	352.54ms (~)	16.06ms (~)	95.4% (~)

_{Median of 10 attempts, 5000 iterations x 10 rounds, 46.4s total}

_{To run a specific benchmark, comment /benchmark <name> where name is one of: attributes, aware, class, default, forwarding, merge, named-slots, no-attributes, slot}

[ganyicz]

Thanks!

I pushed a refactor to simplify the conditionals inside getStaticValue() + added a test for that method specifically.