Move SEL/GET buttons to view-bar as grouped button pair

- Moved SEL and GET buttons from topbar to view-bar
- Created button group with consistent styling
- Positioned to the left of Grid/Tree/Graph tabs
- Added spacer for balanced layout

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

deck-frontend/index.html

@@ -17,9 +17,6 @@
           <option value="ch">CH</option>
         </select>
         <button class="btn btn-sm" id="btn-api">API</button>
-        <button class="btn btn-sm" id="btn-sel">SEL</button>
-        <span id="sel-count"></span>
-        <button class="btn btn-sm" id="btn-get">GET</button>
       </div>
       <div class="topbar-center">
         <!-- Taxonomía -->
@@ -60,11 +57,17 @@
 
     <!-- VIEW BAR -->
     <div class="view-bar">
+      <div class="sel-group">
+        <button class="sel-btn" id="btn-sel">SEL</button>
+        <button class="sel-btn" id="btn-get">GET</button>
+        <span id="sel-count"></span>
+      </div>
       <div class="view-tabs">
         <button class="view-tab active" data-view="grid">Grid</button>
         <button class="view-tab" data-view="tree">Tree</button>
         <button class="view-tab" data-view="graph">Graph</button>
       </div>
+      <div class="view-bar-spacer"></div>
     </div>
 
     <!-- GROUPS BAR -->

deck-frontend/src/styles/main.css

@@ -58,7 +58,6 @@ body {
 .btn:hover { border-color: var(--accent); color: var(--text); }
 .btn.active { background: var(--accent); border-color: var(--accent); color: #fff; }
 .btn-sm { padding: 5px 10px; font-size: 0.75em; }
-.sel-count { font-size: 0.7em; margin-left: 4px; opacity: 0.8; }
 
 .search-input {
     width: 300px;
@@ -94,9 +93,38 @@ body {
     border-bottom: 1px solid var(--border);
     display: flex;
     align-items: center;
-    justify-content: center;
+    justify-content: space-between;
     padding: 0 16px;
-    gap: 8px;
+}
+.view-bar-spacer { width: 120px; }
+
+/* === SEL/GET GROUP === */
+.sel-group {
+    display: flex;
+    align-items: center;
+    gap: 2px;
+    background: var(--bg-card);
+    border-radius: 6px;
+    padding: 3px;
+}
+.sel-btn {
+    padding: 5px 12px;
+    background: transparent;
+    border: none;
+    border-radius: 4px;
+    color: var(--text-muted);
+    cursor: pointer;
+    font-size: 0.75em;
+    font-weight: 600;
+    transition: all 0.15s ease;
+}
+.sel-btn:hover { color: var(--text); background: rgba(255,255,255,0.05); }
+.sel-btn.active { background: var(--accent); color: #fff; }
+#sel-count {
+    font-size: 0.7em;
+    color: var(--accent);
+    margin-left: 6px;
+    font-weight: 600;
 }
 
 /* === GROUPS BAR === */