fix(sidebar): move search below Header, remove section chevrons

- Search input now renders between Sidebar.Header and first Section
  instead of above Header (fixes cameleer3-server#120)
- Remove ChevronRight/ChevronDown from section headers — the entire
  row is already clickable, chevrons added visual noise

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

src/design-system/layout/Sidebar/Sidebar.tsx

@@ -1,11 +1,9 @@
-import { type ReactNode } from 'react'
+import { type ReactNode, Children, isValidElement } from 'react'
 import {
   Search,
   X,
   ChevronsLeft,
   ChevronsRight,
-  ChevronRight,
-  ChevronDown,
 } from 'lucide-react'
 import styles from './Sidebar.module.css'
 import { SidebarContext, useSidebarContext } from './SidebarContext'
@@ -124,9 +122,6 @@ function SidebarSection({
         aria-label={open ? `Collapse ${label}` : `Expand ${label}`}
         onKeyDown={(e) => { if (e.key === 'Enter' || e.key === ' ') { e.preventDefault(); onToggle() } }}
       >
-        <span className={styles.treeSectionChevronBtn} aria-hidden="true">
-          {open ? <ChevronDown size={12} /> : <ChevronRight size={12} />}
-        </span>
         {icon && <span className={styles.sectionIcon}>{icon}</span>}
         <span className={styles.treeSectionLabel}>{label}</span>
       </div>
@@ -199,35 +194,50 @@ function SidebarRoot({
           </button>
         )}
 
-        {/* Search (only when expanded and handler provided) */}
-        {onSearchChange && !collapsed && (
-          <div className={styles.searchWrap}>
-            <div className={styles.searchInner}>
-              <span className={styles.searchIcon} aria-hidden="true">
-                <Search size={12} />
-              </span>
-              <input
-                className={styles.searchInput}
-                type="text"
-                placeholder="Filter..."
-                value={searchValue ?? ''}
-                onChange={(e) => onSearchChange(e.target.value)}
-              />
-              {searchValue && (
-                <button
-                  type="button"
-                  className={styles.searchClear}
-                  onClick={() => onSearchChange('')}
-                  aria-label="Clear search"
-                >
-                  <X size={12} />
-                </button>
-              )}
-            </div>
-          </div>
-        )}
+        {/* Render Header first, then search, then remaining children */}
+        {(() => {
+          const childArray = Children.toArray(children)
+          const headerIdx = childArray.findIndex(
+            (child) => isValidElement(child) && child.type === SidebarHeader,
+          )
+          const header = headerIdx >= 0 ? childArray[headerIdx] : null
+          const rest = headerIdx >= 0
+            ? [...childArray.slice(0, headerIdx), ...childArray.slice(headerIdx + 1)]
+            : childArray
 
-        {children}
+          return (
+            <>
+              {header}
+              {onSearchChange && !collapsed && (
+                <div className={styles.searchWrap}>
+                  <div className={styles.searchInner}>
+                    <span className={styles.searchIcon} aria-hidden="true">
+                      <Search size={12} />
+                    </span>
+                    <input
+                      className={styles.searchInput}
+                      type="text"
+                      placeholder="Filter..."
+                      value={searchValue ?? ''}
+                      onChange={(e) => onSearchChange(e.target.value)}
+                    />
+                    {searchValue && (
+                      <button
+                        type="button"
+                        className={styles.searchClear}
+                        onClick={() => onSearchChange('')}
+                        aria-label="Clear search"
+                      >
+                        <X size={12} />
+                      </button>
+                    )}
+                  </div>
+                </div>
+              )}
+              {rest}
+            </>
+          )
+        })()}
       </aside>
     </SidebarContext.Provider>
   )