feat: add group filter to send logs view

- Add groupId query param to GET /api/logs endpoint
- Add group filter dropdown in SendLogs component
- Pass groups list and filter state from admin.vue
- Update useLogs.ts to accept optional groupId parameter
- Add groupId to SendRecord type
- Add i18n keys and CSS for filter UI

admin/assets/css/main.css

@@ -909,7 +909,38 @@ main {
   display: flex;
   align-items: center;
   justify-content: space-between;
+  gap: 12px;
   margin-bottom: 14px;
+  flex-wrap: wrap;
+}
+
+.log-filters {
+  display: flex;
+  align-items: center;
+  gap: 6px;
+}
+
+.filter-label {
+  font-size: 11px;
+  font-weight: 700;
+  letter-spacing: 0.8px;
+  color: var(--muted);
+  text-transform: uppercase;
+}
+
+.filter-select {
+  background: var(--surface);
+  border: 1px solid var(--border);
+  border-radius: var(--radius);
+  color: var(--text);
+  font-size: 13px;
+  padding: 4px 8px;
+  cursor: pointer;
+  outline: none;
+}
+
+.filter-select:focus {
+  border-color: var(--accent);
 }
 
 .log-list {