fix: typed write failures, template rollback, parent and term cleanup

WriteFailed maps to lit_write_failed / lit_partial_write (partial writes are
logged with result partial); old template read before the update; row marker
set before wp_update_post; created terms deleted on rollback; parent must be a
readable non-descendant of a hierarchical type; featured image must be
readable; snapshot keeps empty values; meta comparison after sanitize_meta;
follow-up failures (listener, change log) only add warnings.

Co-Authored-By: Claude Opus 5.5 (1M context) <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01At3V6SjwbMe6eMzVGW3Hs7

tests/Unit/Abilities/AbilityRegistrarTest.php

@@ -7,6 +7,7 @@ namespace LIT\MCP\Tests\Unit\Abilities;
 use Brain\Monkey\Functions;
 use LIT\MCP\Abilities\Ability;
 use LIT\MCP\Abilities\AbilityRegistrar;
+use LIT\MCP\Abilities\WriteFailed;
 use LIT\MCP\Integrations\Integration;
 use LIT\MCP\Integrations\IntegrationRegistry;
 use LIT\MCP\Server\RequestContext;
@@ -156,6 +157,27 @@ final class AbilityRegistrarTest extends TestCase
         unlink($log);
     }
 
+    public function testWriteFailedBecomesItsOwnErrorAndTheDetailIsLogged(): void
+    {
+        $log = (string) tempnam(sys_get_temp_dir(), 'lit-mcp-log');
+        $previous = ini_set('error_log', $log);
+        $ability = $this->ability();
+        $ability->expects('execute')->andThrow(
+            new WriteFailed('Felder konnten nicht gespeichert werden.', false, 5, 811, new RuntimeException('meta /var/www'))
+        );
+
+        try {
+            $result = ($this->registrarFor($ability)->argsFor($ability)['execute_callback'])([]);
+        } finally {
+            ini_set('error_log', (string) $previous);
+        }
+
+        self::assertSame('lit_partial_write', $result->get_error_code());
+        self::assertStringNotContainsString('/var/www', $result->get_error_message());
+        self::assertStringContainsString('meta /var/www', (string) file_get_contents($log));
+        unlink($log);
+    }
+
     public function testRegisterAbilitiesCallsWordPressForEachAbility(): void
     {
         $ability = $this->ability();

tests/Unit/Abilities/ErrorsTest.php

@@ -55,4 +55,38 @@ final class ErrorsTest extends TestCase
             self::assertNotSame('', json_decode($error->get_error_message(), true)['hint']);
         }
     }
+
+    public function testWriteFailedSaysNothingWasSaved(): void
+    {
+        $error = Errors::writeFailed('Felder konnten nicht gespeichert werden.');
+
+        $payload = json_decode($error->get_error_message(), true);
+        self::assertSame('lit_write_failed', $error->get_error_code());
+        self::assertStringContainsString('Nichts wurde gespeichert.', $payload['message']);
+        self::assertStringContainsString('Felder konnten nicht gespeichert werden.', $payload['message']);
+        self::assertStringContainsString('erneut', $payload['hint']);
+    }
+
+    public function testPartialWriteNamesWhatMayHaveBeenSavedAndWarnsAgainstRetrying(): void
+    {
+        $error = Errors::partialWrite('Felder konnten nicht gespeichert werden.', 5, 811);
+
+        $payload = json_decode($error->get_error_message(), true);
+        self::assertSame('lit_partial_write', $error->get_error_code());
+        self::assertStringContainsString('Eintrag 5', $payload['message']);
+        self::assertStringContainsString('Revision 811', $payload['message']);
+        self::assertStringContainsString('lit-content-get', $payload['hint']);
+        self::assertStringContainsString('lit-revisions-list', $payload['hint']);
+        self::assertStringContainsString('nicht einfach wiederholen', $payload['hint']);
+        self::assertSame(5, $payload['post_id']);
+        self::assertSame(811, $payload['revision_id']);
+    }
+
+    public function testPartialWriteWithoutIdSaysADraftMayExist(): void
+    {
+        $payload = json_decode(Errors::partialWrite('Anlegen fehlgeschlagen.')->get_error_message(), true);
+
+        self::assertStringContainsString('Entwurf', $payload['message']);
+        self::assertArrayNotHasKey('post_id', $payload);
+    }
 }

tests/Unit/Abilities/FollowUpTest.php

@@ -0,0 +1,46 @@
+<?php
+
+declare(strict_types=1);
+
+namespace LIT\MCP\Tests\Unit\Abilities;
+
+use LIT\MCP\Abilities\FollowUp;
+use LIT\MCP\Tests\Unit\TestCase;
+use RuntimeException;
+
+final class FollowUpTest extends TestCase
+{
+    public function testReturnsTheResultOfASuccessfulStep(): void
+    {
+        $warnings = [];
+
+        self::assertSame(7, FollowUp::run(static fn (): int => 7, 'ctx', 'Warnung', $warnings));
+        self::assertSame([], $warnings);
+    }
+
+    public function testAFailingStepIsLoggedAndBecomesAWarning(): void
+    {
+        $log = (string) tempnam(sys_get_temp_dir(), 'lit-mcp-log');
+        $previous = ini_set('error_log', $log);
+        $warnings = ['alt'];
+
+        try {
+            $result = FollowUp::run(
+                static function (): void {
+                    throw new RuntimeException('hook kaputt');
+                },
+                'lit/content-create after_save',
+                'Warnung',
+                $warnings
+            );
+        } finally {
+            ini_set('error_log', (string) $previous);
+        }
+
+        self::assertNull($result);
+        self::assertSame(['alt', 'Warnung'], $warnings);
+        self::assertStringContainsString('lit/content-create after_save', (string) file_get_contents($log));
+        self::assertStringContainsString('hook kaputt', (string) file_get_contents($log));
+        unlink($log);
+    }
+}

tests/Unit/Abilities/WriteFailedTest.php

@@ -0,0 +1,32 @@
+<?php
+
+declare(strict_types=1);
+
+namespace LIT\MCP\Tests\Unit\Abilities;
+
+use LIT\MCP\Abilities\WriteFailed;
+use LIT\MCP\Tests\Unit\TestCase;
+use RuntimeException;
+
+final class WriteFailedTest extends TestCase
+{
+    public function testCleanRollbackMapsToWriteFailed(): void
+    {
+        $cause = new RuntimeException('meta kaputt');
+        $failure = new WriteFailed('Felder konnten nicht gespeichert werden.', true, 5, null, $cause);
+
+        self::assertTrue($failure->rolledBack);
+        self::assertSame($cause, $failure->getPrevious());
+        self::assertStringContainsString('meta kaputt', $failure->getMessage());
+        self::assertSame('lit_write_failed', $failure->toError()->get_error_code());
+    }
+
+    public function testIncompleteRollbackMapsToPartialWriteWithTheIds(): void
+    {
+        $error = (new WriteFailed('Felder konnten nicht gespeichert werden.', false, 5, 811))->toError();
+
+        self::assertSame('lit_partial_write', $error->get_error_code());
+        self::assertSame(5, $error->get_error_data()['post_id']);
+        self::assertSame(811, $error->get_error_data()['revision_id']);
+    }
+}