feat: [planning-design] 메뉴/캔버스 경계 드래그 리사이즈 기능 추가

resources/views/rd/planning-design/index.blade.php

@@ -562,9 +562,14 @@
 
 /* Left Menu Panel */
 .sb-menu-panel {
-    width: 160px; flex-shrink: 0; border-right: 1px solid #e2e8f0;
+    flex-shrink: 0; border-right: none;
     padding: 12px 0; font-size: 11px; overflow-y: auto; background: #f8fafc;
 }
+.sb-menu-resizer {
+    width: 5px; flex-shrink: 0; cursor: col-resize; background: #e2e8f0;
+    transition: background .15s;
+}
+.sb-menu-resizer:hover, .sb-menu-resizer.active { background: #818cf8; }
 .sb-menu-section { font-size: 8px; font-weight: 700; color: #94a3b8; padding: 4px 12px; text-transform: uppercase; }
 .sb-menu-item {
     padding: 5px 12px 5px 16px; color: #64748b; cursor: default;
@@ -1484,9 +1489,11 @@
                                 </div>
                             </div>
 
-                            <div class="sb-page-body">
+                            <div class="sb-page-body"
+                                 @mousemove.window="if(_sbMenuResize){ sbMenuWidth = Math.max(80, Math.min(400, _sbMenuResize.startW + $event.clientX - _sbMenuResize.startX)); }"
+                                 @mouseup.window="if(_sbMenuResize){ _sbMenuResize = null; document.querySelector('.sb-menu-resizer.active')?.classList.remove('active'); }">
                                 {{-- Left Menu --}}
-                                <div class="sb-menu-panel">
+                                <div class="sb-menu-panel" :style="'width:' + sbMenuWidth + 'px'">
                                     <div class="sb-menu-logo" x-text="sb.docInfo.projectName || 'LOGO'"></div>
                                     <div class="sb-menu-section">ERP 메뉴</div>
                                     <template x-for="menu in sb.menuTree" :key="menu.name">
@@ -1501,6 +1508,10 @@
                                     </template>
                                 </div>
 
+                                {{-- Menu / Content Resizer --}}
+                                <div class="sb-menu-resizer"
+                                     @mousedown.prevent="_sbMenuResize = { startX: $event.clientX, startW: sbMenuWidth }; $event.target.classList.add('active')"></div>
+
                                 {{-- Content + Description --}}
                                 <div class="sb-content-area">
                                     {{-- Block Editor Area (moved toolbar to sb-topbar above) --}}
@@ -1974,6 +1985,8 @@ function planningCanvas() {
         _sbDrag: null,   // { blk, startX, startY, origX, origY }
         _sbResize: null, // { blk, dir, startX, startY, origW, origH }
         _sbClipboard: null, // copied block data
+        sbMenuWidth: 160,
+        _sbMenuResize: null,
         _sbHistory: [],
         _sbHistoryIdx: -1,
         _sbHistoryPaused: false,