style: Integrate search form and table into single card container

- Consolidate filter/search form with data table in one card
- Separate with <hr class='my-0'> for visual hierarchy
- Remove redundant card-mb spacing and gaps
- Unified layout for Blog, Clients, Inquiries pages
- Cleaner, more cohesive data display

Applied to:
- Blog/Index.cshtml
- Clients/Index.cshtml
- Inquiries/Index.cshtml

Announcements and Faqs already have integrated structure (no search form)

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

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

@@ -4,30 +4,23 @@
 
 <section class="admin-page-shell">
     @await Html.PartialAsync("_AdminPageHeader", new TaxBaik.Web.Models.AdminPageHeaderModel("Customer Requests", "문의 관리", "상담 요청을 상태별로 확인합니다.", "/admin/inquiries/create", "문의 등록"))
-    <form method="get" class="card mb-3">
+    <div class="card">
         <div class="card-body">
-            <div class="row g-3 align-items-end">
-                <div class="col-md-4">
-                    <label class="form-label" for="Status">상태</label>
-                    <input class="form-control" id="Status" name="status" value="@Model.Status" placeholder="new / consulting / contracted ..." />
+            <form method="get">
+                <div class="row g-3 align-items-end">
+                    <div class="col-md-4">
+                        <label class="form-label" for="Status">상태</label>
+                        <input class="form-control" id="Status" name="status" value="@Model.Status" placeholder="new / consulting / contracted ..." />
+                    </div>
+                    <div class="col-md-2 d-grid">
+                        <button class="btn btn-primary" type="submit">필터</button>
+                    </div>
                 </div>
-                <div class="col-md-2 d-grid">
-                    <button class="btn btn-primary" type="submit">필터</button>
-                </div>
-            </div>
+            </form>
         </div>
-    </form>
-    @if (Model.Items.Count == 0)
-    {
-        <div class="card">
-            <div class="card-body">
-                @await Html.PartialAsync("_EmptyState", "문의 목록이 없습니다.")
-            </div>
-        </div>
-    }
-    else
-    {
-        <div class="card">
+        @if (Model.Items.Count > 0)
+        {
+            <hr class="my-0" />
             <div class="table-responsive">
                 <table class="table table-vcenter card-table table-hover">
                     <thead>
@@ -60,8 +53,14 @@
                     </tbody>
                 </table>
             </div>
-        </div>
-    }
+        }
+        else
+        {
+            <div class="card-body">
+                @await Html.PartialAsync("_EmptyState", "문의 목록이 없습니다.")
+            </div>
+        }
+    </div>
 </section>