fix(translate): deduplicate bulk replace buttons with distinct labels

- Rename page-level button to 'Массовая замена по всем запускам'
  (bulk_replace_all key in i18n) to distinguish from run-level button
- Remove duplicate Bulk Replace button from records table header
  in TranslationRunResult (kept only in result header)
- Fix i18n path for bulk_replace_all (was incorrectly in run namespace)

frontend/src/lib/components/translate/RunTabContent.svelte

@@ -376,7 +376,7 @@
             onclick={() => showPageBulkReplace = true}
             class="px-3 py-1.5 text-xs bg-primary text-white rounded hover:bg-primary-hover transition-colors"
           >
-            {_t.translate?.run?.bulk_replace || 'Bulk Replace'}
+            {_t.translate?.bulk_replace?.bulk_replace_all || _t.translate?.run?.bulk_replace || 'Bulk Replace'}
           </button>
         </div>
         <div class="space-y-3">

frontend/src/lib/components/translate/TranslationRunResult.svelte

@@ -476,12 +476,6 @@ import { SvelteSet } from "svelte/reactivity";
 										: (_t.translate?.run?.load_more_records || 'Load more') + ' (' + (recordsTotal - records.length) + ')'}
 								</button>
 							{/if}
-							<button
-								onclick={() => showBulkReplace = true}
-								class="px-2.5 py-1 text-xs bg-primary text-white rounded hover:bg-primary-hover transition-colors"
-							>
-								{_t.translate?.run?.bulk_replace || 'Bulk Replace'}
-							</button>
 						</div>
 					</div>
 

frontend/src/lib/i18n/locales/en/translate.json

@@ -637,6 +637,7 @@
   },
   "bulk_replace": {
     "title": "Bulk Find & Replace",
+    "bulk_replace_all": "Bulk Replace Across All Runs",
     "close": "Close",
     "find_pattern": "Find pattern",
     "find_placeholder": "Enter text or regex pattern...",

frontend/src/lib/i18n/locales/ru/translate.json

@@ -638,6 +638,7 @@
   },
   "bulk_replace": {
     "title": "Массовая замена",
+    "bulk_replace_all": "Массовая замена по всем запускам",
     "close": "Закрыть",
     "find_pattern": "Шаблон поиска",
     "find_placeholder": "Введите текст или регулярное выражение...",