fix: final review minors m-1 to m-8

- m-1: the no-change Divi result carries preview_url/edit_url too
- m-2: overview names replace-text's per-page tree_rev
- m-3: divi-shortform documents validation_failed vs not_found for unknown IDs
- m-4: DiviWriter/DiviPageLoader final (no mocks left), neutral NewDraft
  log detail, snapshots are Etappe 4
- m-5: Tested up to 7.1, changelog completed
- m-6: content-create warns when the extras changed the stored layout
- m-7: deleting a whole section outlines nothing instead of the next one
- m-8: uninstall removes the user meta lit_mcp_log_per_page; readme lists it

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

src/Uninstaller.php

@@ -9,14 +9,15 @@ defined('ABSPATH') || exit;
 /**
  * Removes WP-LIT-MCP's own data (uninstall.php, Task 12): options, the endpoint-check
  * transient, the log-cleanup cron hook and the change log table – on every site of a
- * network.
+ * network – and the Protokoll tab's per-user screen option.
  *
  * Deliberately self-contained (no reference to any other LIT\MCP\* class): uninstall.php
  * is executed by WordPress core standalone, without loading the plugin's main file first,
  * so the Composer/Jetpack autoloader is not guaranteed to have run. The option/hook/table
  * names below are therefore duplicated from Access::OPTION, Abilities\ExposurePolicy::OPTION,
  * Limits::OPTION, ChangeLog\ChangeLogInstaller::VERSION_OPTION, Admin\ConnectionStatus::
- * ENDPOINT_TRANSIENT, ChangeLog\ChangeLogCleanup::HOOK and ChangeLog\ChangeLog::TABLE on
+ * ENDPOINT_TRANSIENT, ChangeLog\ChangeLogCleanup::HOOK, ChangeLog\ChangeLog::TABLE and
+ * Admin\LogTab::PER_PAGE_OPTION on
  * purpose; tests/Unit/UninstallerTest.php and tests/Unit/UninstallTest.php keep them in
  * sync with those constants.
  *
@@ -32,8 +33,14 @@ final class Uninstaller
     private const CRON_HOOK = 'lit_mcp_log_cleanup';
     private const TABLE = 'lit_mcp_log';
 
+    /** Screen option "Einträge pro Seite" of the Protokoll tab (Admin\LogTab::PER_PAGE_OPTION): user meta. */
+    private const USER_META = 'lit_mcp_log_per_page';
+
     public static function run(): void
     {
+        // User meta is shared by every site of a network: removed once, for all users.
+        delete_metadata('user', 0, self::USER_META, '', true);
+
         if (! is_multisite()) {
             self::removeSiteData();