fix(tenancy): add CRUD actions to merchant-users page, fix view URL and icon

- Fix View link to point to /admin/merchant-users/{id} instead of
  /admin/admin-users/{id}
- Add toggle status and delete action buttons to list page
- Add merchant-user detail page with route, template, and JS
- Replace non-existent "briefcase" icon with "office-building"

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

app/modules/tenancy/routes/pages/admin.py

@@ -267,6 +267,27 @@ async def admin_merchant_users_list_page(
     )
 
 
+@router.get(
+    "/merchant-users/{user_id}", response_class=HTMLResponse, include_in_schema=False
+)
+async def admin_merchant_user_detail_page(
+    request: Request,
+    user_id: int = Path(..., description="User ID"),
+    current_user: User = Depends(
+        require_menu_access("merchant-users", FrontendType.ADMIN)
+    ),
+    db: Session = Depends(get_db),
+):
+    """
+    Render merchant user detail view.
+    Shows details for a merchant owner or store team member.
+    """
+    return templates.TemplateResponse(
+        "tenancy/admin/merchant-user-detail.html",
+        get_admin_context(request, db, current_user, user_id=user_id),
+    )
+
+
 # ============================================================================
 # ADMIN USER MANAGEMENT ROUTES (Super Admin Only)
 # ============================================================================