Remove/move/update search mentions in api.php files

Problem/Motivation

@joachim noted that various api.php files mention search. These are the ones I found:

✅ theme.api.php — 6 references, all in documentation examples:

• Lines 51-77: Uses search_result as the example theme hook for hook_theme() — the whole code block example
• Lines 96-97: "to override the display of search results, a theme would add search-result.html.twig"
• Lines 142-155: Uses item_list__search_results as the example for __SUGGESTION syntax, and explains search_theme_suggestions_search_result()
• Lines 1222-1223: Uses search_result as the example for how template names are derived

✅ entity.api.php — 2 areas:

• Lines 318-325: Bullet list in "Other entity hooks" section listing hook_node_search_ranking(), hook_node_search_result(), "Search indexing nodes"
• Lines 1819-1820: hook_entity_view_display_alter example code uses search_index view mode — should use a different view mode to explain

✅ node.api.php — 3 search-specific hooks documented: hook_node_search_result(), hook_node_update_index(), hook_node_search_ranking() — these are defined by the search_node submodule, so they belong there

✅ toolbar.api.php — the hook_toolbar() example just happens to add a generic HTML field to the toolbar, and 'library' => ['search/global'] — that's a hypothetical custom search/global library, not the search module. This is fine as-is.

✅ core.api.php — references to the search plugin system in the plugin architecture docs (lines 1321, 1351, 1406-1407) — these are part of explaining the plugin system using search as an example.

Steps to reproduce

Proposed resolution

Remove/move/update search mentions in api.php files

Remaining tasks

User interface changes

Introduced terminology

API changes

Data model changes

Release notes snippet

LLM disclosure

LLM was used to detail the findings and to resolve them. With human review.