refactor(bulk-actions): extract FloatingActionBar + actionTargets

Second step in the AdminBulkActions decomp. Two new files:

- actionTargets.ts (27 lines): SUBSCRIPTION_LEVEL_ACTIONS set +
  isSubscriptionLevelAction(). The classification is the source of
  truth shared between FloatingActionBar (renders two grouped menus
  when multi-tariff is on) and the parent page (gates selection-count
  semantics + the active-paid count in delete-subscription).

- FloatingActionBar.tsx (304 lines): the bottom-dock selection
  toolbar. Pure presentational — parent owns selection state and
  supplies onAction (opens the modal with the picked action type)
  + onToggleAllSubscriptions. The full 11-item action config (icons
  + label keys + colour classes) lives inside the file as a private
  ActionConfig array.

Parent now imports FloatingActionBar + isSubscriptionLevelAction
from the new modules; the inline ActionConfig interface is gone.

AdminBulkActions.tsx: 1819 → 1517 lines (-302).
Cumulative across the 2-step admin decomp: 2539 → 1517 (-1022, -40%).

src/components/admin/bulkActions/actionTargets.ts

@@ -0,0 +1,27 @@
+import type { BulkActionType } from '../../../api/adminBulkActions';
+
+// ──────────────────────────────────────────────────────────────────
+// Bulk-action target classification.
+//
+// Some actions operate on user-rows (assign promo group, add balance,
+// delete user); others operate on individual subscription-rows
+// (extend, cancel, change tariff, etc.). The set below is the source
+// of truth shared between FloatingActionBar (renders two grouped
+// menus when multi-tariff is on) and the parent page (gates the
+// selection-count semantics and the active-paid count in delete).
+// ──────────────────────────────────────────────────────────────────
+
+export const SUBSCRIPTION_LEVEL_ACTIONS: Set<BulkActionType> = new Set([
+  'extend_subscription',
+  'add_days',
+  'cancel_subscription',
+  'activate_subscription',
+  'change_tariff',
+  'add_traffic',
+  'set_devices',
+  'delete_subscription',
+]);
+
+export function isSubscriptionLevelAction(action: BulkActionType): boolean {
+  return SUBSCRIPTION_LEVEL_ACTIONS.has(action);
+}