feat: port missing Laravel validation rules

[binaryfire]

Summary

Laravel added contains and doesnt_contain validation rules for validating that arrays contain (or don't contain) specific values. This PR brings those rules to Hypervel with full enum support.

---

New Rules

contains

Validates that an array contains all of the specified values:

use Hypervel\Validation\Rule;

$validator = Validator::make($data, [
    'roles' => ['required', 'array', Rule::contains('admin', 'user')],
]);

// Or with enums
$validator = Validator::make($data, [
    'permissions' => Rule::contains(Permission::Read, Permission::Write),
]);

doesnt_contain

Validates that an array does not contain any of the specified values:

use Hypervel\Validation\Rule;

$validator = Validator::make($data, [
    'tags' => ['required', 'array', Rule::doesntContain('banned', 'restricted')],
]);

// Or with enums
$validator = Validator::make($data, [
    'statuses' => Rule::doesntContain(Status::Deleted, Status::Archived),
]);

Rule::dateTime()

Convenience method for validating datetime strings in Y-m-d H:i:s format:

use Hypervel\Validation\Rule;

$validator = Validator::make($data, [
    'published_at' => Rule::dateTime(),
]);

// Equivalent to:
$validator = Validator::make($data, [
    'published_at' => Rule::date()->format('Y-m-d H:i:s'),
]);

---

Changes

New Files

File	Description
src/validation/src/Rules/Contains.php	Contains rule class
src/validation/src/Rules/DoesntContain.php	DoesntContain rule class
tests/Validation/ValidationContainsRuleTest.php	Tests for Contains rule
tests/Validation/ValidationDoesntContainRuleTest.php	Tests for DoesntContain rule

Modified Files

File	Changes
src/validation/src/Rule.php	Added contains(), doesntContain(), dateTime() static methods
src/validation/src/Concerns/ValidatesAttributes.php	Added validateDoesntContain() method
src/translation/lang/en/validation.php	Added messages for can, contains, doesnt_contain

---

Enum Support

Both rules support all enum types:

// String-backed enum
enum Permission: string {
    case Read = 'read';
    case Write = 'write';
}
Rule::contains(Permission::Read); // contains:"read"

// Int-backed enum
enum Priority: int {
    case Low = 1;
    case High = 2;
}
Rule::contains(Priority::High); // contains:"2"

// Unit enum (non-backed)
enum Tag {
    case Featured;
    case Promoted;
}
Rule::contains(Tag::Featured); // contains:"Featured"