refactor(compat): Prüfbausteine nach src/Compatibility, Matrix und ManifestCheck generisch

Requirement, Call, ConstantRequirement, Mirror, Problem, FeatureStatus, CompatibilityMatrix, Manifest, ManifestCheck sowie Fingerprints und LineDiff liegen jetzt im divi-freien Kern. Neu: GlobalRequirement, CompatibilityMatrix::fromProblems(), ManifestCheck-Option signatures, DiviManifestCheck::create() und DiviAreas. Divi-Verhalten unverändert.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

tests/Unit/Compatibility/LineDiffTest.php

@@ -0,0 +1,35 @@
+<?php
+
+declare(strict_types=1);
+
+namespace LIT\MCP\Tests\Unit\Compatibility;
+
+use LIT\MCP\Compatibility\LineDiff;
+use PHPUnit\Framework\TestCase;
+
+final class LineDiffTest extends TestCase
+{
+    public function testShowsChangedLinesWithTwoLinesOfContext(): void
+    {
+        $old = ['a', 'b', 'c', 'd', 'e', 'f', 'g', 'h', 'i'];
+        $new = ['a', 'b', 'c', 'd', 'E', 'f', 'g', 'h', 'i', 'j'];
+
+        self::assertSame(
+            ['  c', '  d', '- e', '+ E', '  f', '  g', '  h', '  i', '+ j'],
+            LineDiff::lines($old, $new)
+        );
+    }
+
+    public function testMarksAGapBetweenDistantChanges(): void
+    {
+        $old = ['a', 'b', 'c', 'd', 'e', 'f', 'g', 'h', 'i', 'j'];
+        $new = ['A', 'b', 'c', 'd', 'e', 'f', 'g', 'h', 'i', 'J'];
+
+        self::assertSame(['- a', '+ A', '  b', '  c', '…', '  h', '  i', '- j', '+ J'], LineDiff::lines($old, $new));
+    }
+
+    public function testEqualInputHasNoLines(): void
+    {
+        self::assertSame([], LineDiff::lines(['a', 'b'], ['a', 'b']));
+    }
+}