feat(tenancy): expandable per-store rows in merchant team table

Member rows now show a store count with expand/collapse chevron.
Clicking expands sub-rows showing each store with:
- Store name and code
- Per-store role badge
- Per-store status (active/pending independently)
- Per-store actions: resend invitation (pending), remove from store

This fixes the issue where a member active on one store but pending
on another showed misleading combined status and actions.

Member-level actions (view, edit profile) stay on the main row.
Store-level actions (resend, remove) are on each sub-row.

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

app/modules/tenancy/static/merchant/js/merchant-team.js

@@ -31,6 +31,9 @@ function merchantTeam() {
         // Filters
         storeFilter: '',
 
+        // Expanded member rows
+        expandedMembers: [],
+
         // Modal states
         showInviteModal: false,
         showEditModal: false,
@@ -128,6 +131,39 @@ function merchantTeam() {
             );
         },
 
+        /**
+         * Toggle expand/collapse for a member's store rows
+         */
+        toggleMemberExpand(userId) {
+            const idx = this.expandedMembers.indexOf(userId);
+            if (idx > -1) {
+                this.expandedMembers.splice(idx, 1);
+            } else {
+                this.expandedMembers.push(userId);
+            }
+        },
+
+        /**
+         * Resend invitation for a specific store membership
+         */
+        async resendStoreInvitation(storeId, userId) {
+            this.saving = true;
+            try {
+                await apiClient.post(
+                    `/merchants/account/team/stores/${storeId}/members/${userId}/resend`
+                );
+
+                Utils.showToast(I18n.t('tenancy.messages.invitation_resent'), 'success');
+                merchantTeamLog.info('Resent invitation for store:', storeId, 'user:', userId);
+                await this.loadTeamData();
+            } catch (error) {
+                merchantTeamLog.error('Failed to resend invitation:', error);
+                Utils.showToast(error.message || 'Failed to resend invitation', 'error');
+            } finally {
+                this.saving = false;
+            }
+        },
+
         /**
          * Open invite modal with reset form
          */