feat: add rate-limited manual refresh button to Log Entries

Adds a Refresh button next to Filters, right-aligned, specific to the
Logs list. Guarded to one click per 5 seconds (button disabled and
re-enabled via a timer) to avoid hammering the server if left clicked
repeatedly.

Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com>

src/i18n/en.json

@@ -302,6 +302,8 @@
     "next": "Next",
     "noResults": "No results found",
     "previous": "Previous",
+    "refresh": "Refresh",
+    "refreshCooldown": "Please wait a few seconds before refreshing again",
     "resetFilters": "Reset",
     "searchFilters": "Search",
     "selectAll": "Select all",