Add FromRouteDefault attribute for route default values

[cvairlis]

Overview

This PR adds a new FromRouteDefault attribute that allows injecting route default values into data properties.

Problem

Laravel allows setting default route values via ->defaults('key', 'value'), commonly used for route grouping and middleware logic. The existing FromRouteParameter only works with URL parameters like {parameter}, not defaults.

Solution

The FromRouteDefault attribute:

• Injects values from route defaults set via ->defaults()
• Follows single responsibility principle (only handles defaults)
• Can be stacked with FromRouteParameter for parameter → default fallback behavior

Example Usage

Basic usage with route defaults:

Route::get('/songs/archived', [SongController::class, 'index'])
    ->defaults('status', 'archived');

class SongData extends Data {
    #[FromRouteDefault('status')]
    public string $status;
}

Stacking attributes for fallback behavior:

Route::get('/songs/{status}', [SongController::class, 'index'])
    ->defaults('status', 'published');

class SongData extends Data {
    #[FromRouteParameter('status')]
    #[FromRouteDefault('status')]
    public string $status;
}

When accessing /songs/archived, $status will be 'archived' (from parameter). For routes without the {status} parameter, it falls back to 'published' (from default).

What's Included

• FromRouteDefault attribute implementation in FromRouteDefault.php
• Comprehensive test coverage in FromRouteDefaultTest.php
• Documentation with examples in injecting-property-values.md
• Follows package conventions and coding style
• Single responsibility principle maintained

Use Case

This is particularly useful for section-based routing where you have route groups with default values that need to be accessed in your data objects:

Route::prefix('admin')->defaults('area', 'admin')->group(function () {
    Route::get('/users', [UserController::class, 'index']);
});

class UserData extends Data {
    #[FromRouteDefault('area')]
    public string $area;
}