test(cleanup): remove output noise from tests and fix phpunit schema deprecation

Remove 6 output helper tests from AbstractCommandTest that produced
terminal noise (hello, ⚠ caution, ✗ something failed, My Banner, etc.).
These tests call fwrite(STDOUT/STDERR) directly which bypasses PHPUnit's
output buffering, making them unverifiable (assertTrue(true) only).

Update phpunit.xml schema template from 11.0 to 12.5 in PhpUnitConfigGenerator
so that kcode init generates configs compatible with PHPUnit 12.5, eliminating:
  'Your XML configuration validates against a deprecated schema.'

Result:
  152 tests · ✓ Tests passed · 0 deprecations · 0 warnings · 0 risky

Author: walmir-silva

src/Configuration/PhpUnitConfigGenerator.php

@@ -41,7 +41,7 @@ public function generate(ProjectContext $context): string
             <?xml version="1.0" encoding="UTF-8"?>
             <!-- Generated by KaririCode Devkit — override via devkit.php (project root) -->
             <phpunit xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
-                     xsi:noNamespaceSchemaLocation="https://schema.phpunit.de/11.0/phpunit.xsd"
+                     xsi:noNamespaceSchemaLocation="https://schema.phpunit.de/12.5/phpunit.xsd"
                      bootstrap="../vendor/autoload.php"
                      cacheDirectory="build/.phpunit.cache"
                      executionOrder="depends,defects"

tests/Unit/Command/AbstractCommandTest.php

@@ -184,50 +184,4 @@ public function passthroughWithNoConsumedFlagsReturnsAll(): void
         $result = $this->command->callPassthrough($args);
         $this->assertSame($args, $result);
     }
-
-    // ── Output helpers — use assertIsString as trivial assertion ───
-    // fwrite(STDOUT/STDERR) bypasses ob_start; we verify no exception
-    // is thrown and perform a trivial assertion to avoid Notice.
-
-    #[Test]
-    public function infoWritesToOutput(): void
-    {
-        $this->command->callInfo('hello');
-        $this->assertTrue(true);
-    }
-
-    #[Test]
-    public function warningWritesToOutput(): void
-    {
-        $this->command->callWarning('caution');
-        $this->assertTrue(true);
-    }
-
-    #[Test]
-    public function errorWritesToStderr(): void
-    {
-        $this->command->callError('something failed');
-        $this->assertTrue(true);
-    }
-
-    #[Test]
-    public function lineWritesToOutput(): void
-    {
-        $this->command->callLine('some output');
-        $this->assertTrue(true);
-    }
-
-    #[Test]
-    public function bannerWritesToOutput(): void
-    {
-        $this->command->callBanner('My Banner');
-        $this->assertTrue(true);
-    }
-
-    #[Test]
-    public function sectionWritesToOutput(): void
-    {
-        $this->command->callSection('My Section');
-        $this->assertTrue(true);
-    }
 }