style: Add separator class to all table-responsive containers

Apply .table-responsive--separator to all pages with table containers (Announcements, FAQs, TaxProfiles, Companies) for consistent spacing and visual hierarchy.

Co-Authored-By: Claude Haiku 4.5 <noreply@anthropic.com>

src/TaxBaik.Web/Pages/Admin/Announcements/Index.cshtml

@@ -15,7 +15,7 @@
     else
     {
         <div class="card">
-            <div class="table-responsive">
+            <div class="table-responsive table-responsive--separator">
                 <table class="table table-vcenter card-table table-hover">
                     <thead>
                         <tr>

src/TaxBaik.Web/Pages/Admin/Companies/Index.cshtml

@@ -15,7 +15,7 @@
     else
     {
         <div class="card">
-            <div class="table-responsive">
+            <div class="table-responsive table-responsive--separator">
                 <table class="table table-vcenter card-table">
                     <thead>
                         <tr><th>코드</th><th>회사명</th><th>담당자</th><th>활성</th></tr>

src/TaxBaik.Web/Pages/Admin/Faqs/Index.cshtml

@@ -15,7 +15,7 @@
     else
     {
         <div class="card">
-            <div class="table-responsive">
+            <div class="table-responsive table-responsive--separator">
                 <table class="table table-vcenter card-table table-hover">
                     <thead>
                         <tr><th>질문</th><th>카테고리</th><th>활성</th><th>정렬</th><th class="text-end">작업</th></tr>

src/TaxBaik.Web/Pages/Admin/TaxProfiles/Index.cshtml

@@ -15,7 +15,7 @@
     else
     {
         <div class="card">
-            <div class="table-responsive">
+            <div class="table-responsive table-responsive--separator">
                 <table class="table table-vcenter card-table">
                     <thead>
                         <tr><th>고객ID</th><th>사업유형</th><th>세무위험</th><th>다음신고일</th></tr>